Don't reimplement move-if-change badly

* Makefile.in (gl-stamp): Generate globals.h through the use of
move-if-change.
(globals.h): Replace with empty command.

src/ChangeLog

+2015-01-31  Andreas Schwab  <schwab@linux-m68k.org>
+
+	* Makefile.in (gl-stamp): Generate globals.h through the use of
+	move-if-change.
+	(globals.h): Replace with empty command.
+
 2015-01-31  Eli Zaretskii  <eliz@gnu.org>
 
 	* keyboard.c (kbd_buffer_store_event_hold): Ignore FOCUS_OUT_EVENT

src/Makefile.in

@@ -494,11 +494,17 @@ buildobj.h: Makefile
 
 GLOBAL_SOURCES = $(base_obj:.o=.c) $(NS_OBJC_OBJ:.o=.m)
 
+AM_V_GLOBALS = $(am__v_GLOBALS_@AM_V@)
+am__v_GLOBALS_ = $(am__v_GLOBALS_@AM_DEFAULT_V@)
+am__v_GLOBALS_0 = @echo "  GEN     " globals.h;
+am__v_GLOBALS_1 =
+
 gl-stamp: $(libsrc)/make-docfile$(EXEEXT) $(GLOBAL_SOURCES)
-	$(AM_V_GEN)$(libsrc)/make-docfile -d $(srcdir) -g $(obj) >$@
+	$(AM_V_GLOBALS)$(libsrc)/make-docfile -d $(srcdir) -g $(obj) > globals.tmp
+	$(AM_V_at)$(top_srcdir)/build-aux/move-if-change globals.tmp globals.h
+	$(AM_V_at)echo timestamp > $@
 
-globals.h: gl-stamp
-	$(AM_V_GEN)cmp $< $@ >/dev/null || cp $< $@
+globals.h: gl-stamp; @true
 
 $(ALLOBJS): globals.h