Remove unneeded #define POSIX

* src/s/gnu-linux.h, src/s/sol2-6.h: No longer define POSIX,
unused since 2011-01-17 change to systty.h.

* admin/CPP-DEFINES: Related edit.

admin/CPP-DEFINES

@@ -192,7 +192,6 @@ O_RDONLY
 O_RDWR
 PAGESIZE
 PENDING_OUTPUT_COUNT
-POSIX
 PREFER_VSUSP
 PTY_ITERATION
 PTY_NAME_SPRINTF

src/ChangeLog

 2012-07-11  Glenn Morris  <rgm@gnu.org>
+	* s/gnu-linux.h, s/sol2-6.h: No longer define POSIX,
+	unused since 2011-01-17 change to systty.h.
+
 	* s/aix4-2.h, s/bsd-common.h, s/cygwin.h, s/darwin.h, s/gnu-linux.h:
 	* s/hpux10-20.h, s/template.h, s/usg5-4-common.h:
 	Move HAVE_PTYS and HAVE_SOCKETS to configure.

src/s/gnu-linux.h

@@ -71,7 +71,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    your system and must be used only through an encapsulation
    (Which you should place, by convention, in sysdep.c).  */
 
-#define POSIX                 /* affects getpagesize.h and systty.h */
 
 /* This is to work around mysterious gcc failures in some system versions.
    It is unlikely that Emacs changes will work around this problem;

src/s/sol2-6.h

@@ -24,8 +24,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 /* This triggers a conditional in xfaces.c.  */
 #define XOS_NEEDS_TIME_H
 
-#define POSIX
-
 /* This is the same definition as in usg5-4-common.h, but with sigblock/sigunblock
    rather than sighold/sigrelse, which appear to be BSD4.1 specific.
    It may also be appropriate for SVR4.x