GitLab

Merge from gnulib, incorporating:
2012-08-24 execinfo: port to FreeBSD
2012-08-22 execinfo: new module
* admin/merge-gnulib (GNULIB_MODULES): Add execinfo.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* lib/execinfo.c, lib/execinfo.in.h, m4/execinfo.m4: New files.
* src/alloc.c [ENABLE_CHECKING]: Include <execinfo.h>.
(die) [ENABLE_CHECKING]: Print a backtrace if available.
* src/Makefile.in (LIB_EXECINFO): New macro.
(LIBES): Use it.

(gc_in_progress, abort_on_gc)
(setjmp_tested_p) [!GC_SAVE_REGISTERS_ON_STACK && !GC_SETJMP_WORKS]:
(dont_register_blocks) [GC_MALLOC_CHECK]:
(suppress_checking) [ENABLE_CHECKING]: Now bool, not int.
(check_string_bytes, make_specified_string, memory_full)
(live_string_p, live_cons_p, live_symbol_p, live_float_p)
(live_misc_p, live_vector_p, live_buffer_p, mark_maybe_object)
(mark_stack, valid_pointer_p, make_pure_string)
(Fgarbage_collect, survives_gc_p, gc_sweep):
Use bool for booleans, instead of int.
(test_setjmp) [!GC_SAVE_REGISTERS_ON_STACK && !GC_SETJMP_WORKS]:
Remove unused local.
* alloc.c (PURE_POINTER_P):
* lisp.h (STRING_MULTIBYTE): Document that it returns a boolean.
* editfns.c (Fformat):
* fileio.c (Fexpand_file_name, Fsubstitute_in_file_name)
(Fdo_auto_save):
* fns.c (sweep_weak_table):
* lisp.h (suppress_checking, push_message, survives_gc_p)
(make_pure_string, gc_in_progress, abort_on_gc):
* lread.c (readchar, read1):
* print.c (Fprin1_to_string):
* xdisp.c (push_message):
Use bool for booleans affected directly or indirectly by
alloc.c's changes.

* buffer.c (set_buffer_overlays_before): Move here from buffer.h,
and rename from buffer_overlays_set_before.
(set_buffer_overlays_after): Move here from buffer.h, and rename
from buffer_overlays_set_after.
* buffer.h (buffer_intervals): Rename from buffer_get_intervals.
All uses changed.
(set_buffer_intervals): Rename from buffer_set_intervals.
* intervals.c (set_interval_object): Move here from intervals.h,
and rename from interval_set_object.
(set_interval_left): Move here from intervals.h, and rename from
interval_set_left.
(set_interval_right): Move here from intervals.h, and rename from
interval_set_right.
(copy_interval_parent): Move here from intervals.h, and rename from
interval_copy_parent.
* intervals.h (set_interval_parent): Rename from interval_set_parent.
(set_interval_plist): Rename from interval_set_plist.
Return void, not Lisp_Object, since no caller uses the result.
* lisp.h (string_intervals): Rename from string_get_intervals.
(set_string_intervals): Rename from string_set_intervals.

* buffer.h (enum overlay_type): Remove.
(buffer_get_overlays, buffer_set_overlays): Likewise.
(buffer_set_overlays_before, buffer_set_overlays_after):
New function.  Adjust users.
(unchain_both): Add eassert.

* buffer.c (unchain_both): New function.
* buffer.h (buffer_get_overlays, buffer_set_overlays):
(buffer_has_overlays): New function.
(enum overlay_type): New enum.
* alloc.c, buffer.c, editfns.c, fileio.c, indent.c:
* insdel.c, intervals.c, print.c, xdisp.c: Adjust users.

* alloc.c (mark_interval_tree): Remove.
(MARK_INTERVAL_TREE): Simplify.
(UNMARK_BALANCE_INTERVALS): Remove.  Adjust users.
* intervals.c (buffer_balance_intervals): New function.
(graft_intervals_into_buffer): Adjust indentation.
(set_intervals_multibyte): Simplify.
* buffer.h (BUF_INTERVALS): Remove.
(buffer_get_intervals, buffer_set_intervals): New function.
* alloc.c, buffer.c, editfns.c, fileio.c, indent.c, insdel.c:
* intervals.c, textprop.c: Adjust users.

* lisp.h (STRING_INTERVALS, STRING_SET_INTERVALS): Remove.
(string_get_intervals, string_set_intervals): New function.
* alloc.c, buffer.c, editfns.c, fns.c, insdel.c, intervals.c:
* lread.c, print.c, textprop.c: Adjust users.

* intervals.h (NULL_INTERVAL, DEFAULT_INTERVAL): Remove.
(NULL_INTERVAL_P): Likewise.  Adjust users.
(FRONT_STICKY_P, END_NONSTICKY_P, FRONT_NONSTICKY_P): Adjust
comment.  Move under #if 0.
* alloc.c, buffer.c, editfns.c, fns.c, insdel.c, intervals.c:
* print.c, syntax.c, textprop.c, xdisp.c: Adjust users.

* src/lisp.h (struct Lisp_Symbol): Change xname to meaningful
name since all xname users are fixed long time ago.  Do not use
INTERNAL_FIELD.
(set_symbol_name, set_symbol_function, set_symbol_plist):
(set_symbol_next, set_overlay_plist): New function.
(struct Lisp_Cons): Do not use INTERNAL_FIELD.
(struct Lisp_Overlay): Likewise.
(CVAR, MVAR, SVAR): Remove.
* src/alloc.c, src/buffer.c, src/buffer.h, src/bytecode.c:
* src/cmds.c, src/data.c, src/doc.c, src/eval.c, src/fns.c:
* src/keyboard.c, src/lread.c, src/nsselect.m, src/xterm.c:
Adjust users.
* src/.gdbinit: Change to use name field of struct Lisp_Symbol
where appropriate.
* admin/coccinelle/overlay.cocci, admin/coccinelle/symbol.cocci:
Remove.

* intervals.h (interval_set_parent, interval_set_object):
(interval_set_left, interval_set_right, interval_set_plist):
(interval_copy_parent): New function.
(SET_INTERVAL_OBJECT, SET_INTERVAL_PARENT, INTERVAL_PTR_SIZE): Remove.
(RESET_INTERVAL, COPY_INTERVAL_CACHE, MERGE_INTERVAL_CACHE): Adjust
indentation.
(INTERVAL_SIZE): Remove.  Adjust users.
* alloc.c, intervals.c, lread.c, textprop.c: Use new functions.

* window.h (WGET): Remove.
(struct window): Do not use INTERNAL_FIELD.
* alloc.c, buffer.c, composite.c, dispextern.h, dispnew.c, editfns.c:
* fileio.c, font.c, fontset.c, frame.c, frame.h, fringe.c, indent.c:
* insdel.c, keyboard.c, keymap.c, lisp.h, minibuf.c, msdos.c, nsfns.m:
* nsmenu.m, nsterm.m, print.c, textprop.c, w32fns.c, w32menu.c:
* w32term.c, window.c, xdisp.c, xfaces.c, xfns.c, xmenu.c, xterm.c:
Adjust users.

* alloc.c (XMALLOC_HEADER_ALIGNMENT, roundup_size):
(union aligned_Lisp_Symbol, union aligned_Lisp_Misc):
(mark_maybe_pointer, pure_alloc): Change to use GCALIGNMENT.

* window.h (WGET, WSET): New macros similar to AREF and ASET.
* alloc.c, buffer.c, composite.c, dispextern.h, dispnew.c, editfns.c:
* fileio.c, font.c, fontset.c, frame.c, frame.h, fringe.c, indent.c:
* insdel.c, keyboard.c, keymap.c, lisp.h, minibuf.c, msdos.c, nsfns.m:
* nsmenu.m, nsterm.m, print.c, textprop.c, w32fns.c, w32menu.c:
* w32term.c, window.c, xdisp.c, xfaces.c, xfns.c, xmenu.c, xterm.c:
Adjust users.

* lisp.h (header_size, bool_header_size, word_size): Now here.
(struct Lisp_Vector): Add comment.
(struct Lisp_Bool_Vector): Move up to define handy constants.
(VECSIZE, PSEUDOVECSIZE): Simplify.
(SAFE_ALLOCA_LISP): Use new constant.  Adjust indentation.
* buffer.c, buffer.h, bytecode.c, callint.c, eval.c, fns.c:
* font.c, fontset.c, keyboard.c, keymap.c, macros.c, menu.c:
* msdos.c, w32menu.c, w32term.h, window.c, xdisp.c, xfaces.c:
* xfont.c, xmenu.c: Use word_size where appropriate.

These casts are no longer needed now that we assume C89 or later,
since they involve casting to or from void *.
* alloc.c (make_pure_string, make_pure_c_string, pure_cons)
(make_pure_float, make_pure_vector):
* lisp.h (SAFE_ALLOCA, SAFE_ALLOCA_LISP):
* macros.c (Fstart_kbd_macro):
* menu.c (find_and_return_menu_selection):
* minibuf.c (read_minibuf_noninteractive):
* sysdep.c (closedir):
* xdisp.c (x_produce_glyphs):
* xfaces.c (compare_fonts_by_sort_order):
* xfns.c (x_real_positions, select_visual):
* xselect.c (x_stop_queuing_selection_requests)
(x_get_window_property, x_get_window_property_as_lisp_data):
* xterm.c (x_set_frame_alpha, x_find_modifier_meanings):
Remove unnecessary pointer casts.
* alloc.c (record_xmalloc): New function.
* lisp.h (record_xmalloc): New decl.
(SAFE_ALLOCA): Now takes just one arg -- the size -- and acts
more like a function.  This is because the pointer cast is not
needed.  All uses changed.
* print.c (print_string, print_error_message): Avoid length recalc.

* lib-src/profile.c (SYSTIME_INLINE): Define.
* nt/config.nt: Sync with autogen/config.in.
(_GL_INLINE, _GL_EXTERN_INLINE, _GL_INLINE_HEADER_BEGIN)
(_GL_INLINE_HEADER_END): New macros.
* src/buffer.h (BUFFER_INLINE):
* src/category.h (CATEGORY_INLINE):
* src/character.h (CHARACTER_INLINE):
* src/charset.h (CHARSET_INLINE):
* src/composite.h (COMPOSITE_INLINE):
* src/dispextern.h (DISPEXTERN_INLINE):
* src/lisp.h (LISP_INLINE):
* src/systime.h (SYSTIME_INLINE):
New macro, replacing 'static inline' in this header.
* src/buffer.h, src/category.h, src/character.h, src/charset.h:
* src/composite.h, src/dispextern.h, lisp.h, systime.h:
Use INLINE_HEADER_BEGIN, INLINE_HEADER_END.
* src/alloc.c (LISP_INLINE):
* src/buffer.c (BUFFER_INLINE):
* src/category.c (CATEGORY_INLINE):
* src/character.c (CHARACTER_INLINE):
* src/charset.c (CHARSET_INLINE):
* src/composite.c (COMPOSITE_INLINE):
* src/dispnew.c (DISPEXTERN_INLINE):
* src/sysdep.c (SYSTIME_INLINE):
Define to EXTERN_INLINE, so that the corresponding functions
are compiled into code.
* src/conf_post.h (INLINE, EXTERN_INLINE, INLINE_HEADER_BEGIN)
(INLINE_HEADER_END): New macros.
* src/lisp.h (PSEUDOVECTOR_FLAG): Now a macro as well as a constant,
since it's used in non-static inline functions now.

* src/lisp.h (struct Lisp_Cons): Use INTERNAL_FIELD.
Remove obsolete comment.
(MVAR): New macro.
(struct Lisp_Overlay): Use INTERNAL_FIELD.
* src/alloc.c, src/buffer.c, src/buffer.h, src/fns.c: Adjust users.
* admin/coccinelle/overlay.cocci: Semantic patch to replace direct
access to Lisp_Object members of struct Lisp_Overlay to MVAR.

* src/lisp.h (SVAR): New macro.  Adjust users.
* src/alloc.c, src/bytecode.c, src/cmds.c, src/data.c, src/doc.c, src/eval.c:
* src/fns.c, src/keyboard.c, src/lread.c, src/xterm.c: Users changed.
* admin/coccinelle/symbol.cocci: Semantic patch to replace direct
access to Lisp_Object members of struct Lisp_Symbol to SVAR.

* src/window.h (WVAR): New macro.
(struct window): Change Lisp_Object members to INTERNAL_FIELD.
* src/alloc.c, src/buffer.c, src/composite.c, src/dispextern.h:
* src/dispnew.c, src/editfns.c, src/fileio.c, src/font.c, src/fontset.c:
* src/frame.c, src/frame.h, src/fringe.c, src/indent.c, src/insdel.c:
* src/keyboard.c, src/keymap.c, src/lisp.h, src/minibuf.c, src/nsterm.m:
* src/print.c, src/textprop.c, src/w32fns.c, src/w32menu.c, src/w32term.c:
* src/window.c, src/xdisp.c, src/xfaces.c, src/xfns.c, src/xmenu.c:
* src/xterm.c: Users changed.
* admin/coccinelle/window.cocci: Semantic patch to replace direct
access to Lisp_Object members of struct window to WVAR.

* src/lisp.h (INTERNAL_FIELD): New macro.
* src/buffer.h (BUFFER_INTERNAL_FIELD): Removed.
(BVAR): Change to use INTERNAL_FIELD.
* src/keyboard.h (KBOARD_INTERNAL_FIELD): Likewise.
(KVAR): Change to use INTERNAL_FIELD.
* src/frame.h (FVAR): New macro.
(struct frame): Use INTERNAL_FIELD for all Lisp_Object fields.
* src/alloc.c, src/buffer.c, src/data.c, src/dispnew.c, src/dosfns.c
* src/eval.c, src/frame.c, src/fringe.c, src/gtkutil.c, src/minibuf.c
* src/nsfns.m, src/nsterm.m, src/print.c, src/term.c, src/w32fns.c
* src/w32menu.c, src/w32term.c, src/window.c, src/window.h, src/xdisp.c
* src/xfaces.c, src/xfns.c, src/xmenu.c, src/xterm.c: Users changed.
* admin/coccinelle/frame.cocci: Semantic patch to replace direct
access to Lisp_Object members of struct frame to FVAR.

This no-op macro hasn't been needed for many years.
* src/regex.c (SWITCH_ENUM_CAST) [!emacs]: Likewise.

* alloc.c (gdb_make_enums_visible) [USE_LSB_TAG]: Add lsb_bits.
* lisp.h (enum lsb_bits) [USE_LSB_TAG]: New enum, for
gdb_make_enums_visible.
(TYPEMASK, VALMASK) [USE_LSB_TAGS]: Now enum constants, not macros.
(DIRECTORY_SEP): Now a constant, not a macro.

* lisp.h (min, max): Move earlier, because they're used earlier now.
(INTMASK, ARRAY_MARK_FLAG, PSEUDOVECTOR_FLAG, VALMASK)
(CHAR_TABLE_STANDARD_SLOTS, CHARTAB_SIZE_BITS_0)
(CHARTAB_SIZE_BITS_1, CHARTAB_SIZE_BITS_2, CHARTAB_SIZE_BITS_3)
(DEFAULT_HASH_SIZE, COMPILED_ARGLIST, COMPILED_BYTECODE)
(COMPILED_CONSTANTS, COMPILED_STACK_DEPTH, COMPILED_DOC_STRING)
(COMPILED_INTERACTIVE, CHAR_ALT, CHAR_SUPER, CHAR_HYPER, CHAR_SHIFT)
(CHAR_CTL, CHAR_META, CHAR_MODIFIER_MASK, CHARACTERBITS)
(MANY, UNEVALLED, FLOAT_TO_STRING_BUFSIZE, MAX_ALLOCA):
Now constants, for GDB.  They need not be macros.
(MOST_POSITIVE_FIXNUM, MOST_NEGATIVE_FIXNUM, STRING_BYTES_BOUND):
Now constants, for GDB, as well as macros, for static initializers.
(CHAR_TABLE_STANDARD_SLOTS, CHAR_TABLE_EXTRA_SLOTS):
Move to after the definition of struct Lisp_Char_Table,
since the former now needs that type defined.
(enum CHARTAB_SIZE_BITS, enum CHAR_TABLE_STANDARD_SLOTS)
(enum DEFAULT_HASH_SIZE, enum Lisp_Compiled, enum char_bits)
(enum maxargs, enum FLOAT_TO_STRING_BUFSIZE, enum MAX_ALLOCA):
New enums, for gdb_make_enums_visible.
(GLYPH_MODE_LINE_FACE): Remove; unused.
* alloc.c (STRING_BYTES_MAX): Now a constant, now a macro.
(gdb_make_enums_visible): Add enum CHARTAB_SIZE_BITS, enum
CHAR_TABLE_STANDARD_SLOTS, enum char_bits, enum DEFAULT_HASH_SIZE,
enum FLOAT_TO_STRING_BUFSIZE, enum Lisp_Bits, enum Lisp_Compiled,
enum maxargs, enum MAX_ALLOCA.
(ARRAY_MARK_FLAG_VAL, PSEUDOVECTOR_FLAG_VAL, VALMASK_VAL): Remove.
(ARRAY_MARK_FLAG, PSEUDOVECTOR_FLAG, VALMASK): Remove;
no longer needed, now that they are done in lisp.h.

* alloc.c (GC_STRING_BYTES, CHECK_STRING_BYTES): Remove.  Convert
all users to STRING_BYTES or string_bytes if GC_CHECK_STRING_BYTES.
(check_string_bytes): Define to empty if not GC_CHECK_STRING_BYTES.
(check_sblock, compact_small_strings): Simplify.

* lisp.h (HIDE_LISP_IMPLEMENTATION): Remove as useless for a long
time.  Adjust users.
(CHECK_CONS_LIST): Remove.  Convert all users to check_cons_list.

* alloc.c (Fgarbage_collect): Rename t1 to meaningful start.  Fix
zombies percentage calculation.  Simplify elapsed time calculation.

* .bzrignore: Add lib/stdalign.h.
* config.bat: Do not set NO_DECL_ALIGN; no longer needed.
Copy lib/stdalign.in.h to lib/stdalign.in-h as needed.
* configure.ac (HAVE_ATTRIBUTE_ALIGNED): Remove the code that
fiddles with this, as gnulib now does this for us.
* admin/merge-gnulib: Add environ, stdalign.
* m4/environ.m4: New file, from gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* lib/stdalign.in.h, m4/stdalign.m4: New files, from gnulib.
* sed2v2.inp (HAVE_ATTRIBUTE_ALIGNED): Remove edit.
* sedlibmk.inp (STDALIGN_H, @GL_GENERATE_STDALIGN_H_TRUE@)
(GL_GENERATE_STDALIGN_H_FALSE): New edits.
* nt/config.nt (HAVE_ATTRIBUTE_ALIGNED): Remove.
* src/alloc.c (XMALLOC_BASE_ALIGNMENT, GC_POINTER_ALIGNMENT, pure_alloc):
Simplify by using alignof.
(pure_alloc) [! USE_LSB_TAG]: Don't over-align EMACS_INT values.
* src/lisp.h: Include <stdalign.h>.
(GCALIGNMENT): New macro and constant.
(DECL_ALIGN): Remove.  All uses replaced by alignas (GCALIGNMENT).
(USE_LSB_TAG): ifdef on alignas, not on DECL_ALIGN.
(stdalign): New macro, if not already defined.

 src/alloc.c (listn): Fix the order the arguments are consed onto the list.

 src/lisp.h (enum constype): Use CONSTYPE_HEAP and CONSTYPE_PURE for
 enumeration constants, as PURE and HEAP are too general, and clash
 with other headers and sources, such as gmalloc.c and the
 MS-Windows system headers.  All users changed.

* alloc.c, editfns.c, marker.c, lisp.h: Revert.
Lots of crashes reported by Chong Yidong <cyd@gnu.org>.

* .gdbinit (xgetptr, xgetint, xgettype): Set $bugfix in different
arms of an 'if', not using conditional expressions; otherwise GDB
complains about the types in the unevaluated arm when the argument
is an integer literal.
(xgetint): Simplify expression.
* alloc.c (gdb_make_enums_visible): New constant.  This ports to
GCC 3.4.2 the export of symbols to GDB.  Problem reported by Eli
Zaretskii in <http://bugs.gnu.org/1995-05-30T23:07:27Z!kwzh@gnu.org#13>.
* lisp.h (PUBLISH_TO_GDB): Remove.  All uses removed.  No longer
needed now that we have gdb_make_enums_visible.
(enum CHECK_LISP_OBJECT_TYPE, enum Lisp_Bits, enum More_Lisp_Bits)
(enum enum_USE_LSB_TAG):
New enum types, packaging up enums that need to be exported to GDB.

* lisp.h (enum constype): New datatype.
(listn): New prototype.
* alloc.c (listn): New function.
(Fmemory_use_count, syms_of_alloc): Use it.
* buffer.c (syms_of_buffer): Likewise.
* callint.c (syms_of_callint): Likewise.
* charset.c (define_charset_internal): Likewise.
* coding.c (syms_of_coding): Likewise.
* keymap.c (syms_of_keymap): Likewise.
* search.c (syms_of_search): Likewise.
* syntax.c (syms_of_syntax): Likewise.
* w32.c (init_environment): Likewise.
* w32fns.c (Fw32_battery_status, syms_of_w32fns): Likewise.
* xdisp.c (syms_of_xdisp): Likewise.
* xfns.c (syms_of_xfns): Likewise.

* lisp.h (struct Lisp_Excursion): New data type.
(PVEC_EXCURSION): New pseudovector type.
(XEXCURSION, XSETEXCURSION, EXCURSIONP): Convenient macros
to deal with it.  Adjust comments.
(init_marker, attach_marker): New prototype.
(unchain_marker): Adjust prototype.
* marker.c (attach_marker): Change to global.
(init_marker): New function.
* alloc.c (Fmake_marker, build_marker): Use it.
(build_marker): More easserts.
(mark_object): Handle struct Lisp_Excursion.
* editfns.c (save_excursion_save, save_excursion_restore):
Reimplement to use struct Lisp_Excursion.  Add comments.

* alloc.c (ARRAY_MARK_FLAG_VAL, PSEUDOVECTOR_FLAG_VAL, VALMASK_VAL)
(ARRAY_MARK_FLAG, PSEUDOVECTOR_FLAG, VALMASK): Move these here from
emacs.c, as this is a more-suitable home.  Had this been done earlier
the fix for 1995-05-30T23:07:27Z!kwzh@gnu.org would have avoided some of the problems noted in
<http://bugs.gnu.org/1995-05-30T23:07:27Z!kwzh@gnu.org#13> by Eli Zaretskii, as the scope problems
would have been more obvious.
* emacs.c (gdb_CHECK_LISP_OBJECT_TYPE, gdb_DATA_SEG_BITS)
(gdb_GCTYPEBITS, gdb_USE_LSB_TAG)
(CHECK_LISP_OBJECT_TYPE, DATA_SEG_BITS, GCTYPEBITS, USE_LSB_TAG):
Remove; now done in lisp.h.
* lisp.h (PUBLISH_TO_GDB): New macro.
(GCTYPEBITS, USE_LSB_TAG, CHECK_LISP_OBJECT_TYPE, enum pvec_type)
(DATA_SEG_BITS): Use it.
(GCTYPEBITS, USE_LSB_TAG): Now also an enum, for GDB.
(CHECK_LISP_OBJECT_TYPE, DATA_SEG_BITS): Now just an enum, for GDB.
* mem-limits.h (EXCEEDS_LISP_PTR): Redo so that DATA_SEG_BITS need
not be usable in #if.  This simplifies things.

* alloc.c (allocate_misc): Change to static.  Add argument to
specify the subtype.  Adjust comment and users.
(build_overlay): New function.
* buffer.c (copy_overlays, Fmake_overlay): Use it.
* lisp.h (struct Lisp_Overlay): Remove obsolete comment.
(allocate_misc): Remove prototype.
(build_overlay): Add prototype.

* alloc.c (GC_DEFAULT_THRESHOLD): New macro.
(Fgarbage_collect): Use it.  Change minimum to 1/10 of default.
(free_cons, free_misc): Subtract object size from consing_since_gc.

* alloc.c (Qheap): New symbol.
(syms_of_alloc): DEFSYM it.
(Fgarbage_collect): If DOUG_LEA_MALLOC, add mallinfo data.
(Fmemory_free): Remove.
(syms_of_alloc): Don't defsubr it.
* buffer.c (Fcompact_buffer): Remove.
(syms_of_buffer): Don't defsubr it.

Verify that inlining is always possible (GCC 4.7.1, -O3 -Winline).
* lisp.h (consing_since_gc, gc_relative_threshold)
(memory_full_cons_threshold): Revert declaration.
(maybe_gc): Remove prototype, define as inline.
* alloc.c: Remove old commented-out code.
(consing_since_gc, gc_relative_threshold)
(memory_full_cons_threshold): Revert to global.
(maybe_gc): Remove.