* configure.ac (opsysfile): Use bsd-common on gnu systems.

* src/s/gnu.h: Remove file, which is now empty.

* configure.ac (GNU_LIBRARY_PENDING_OUTPUT_COUNT): Move here from src/s.

* src/s/gnu.h, src/s/gnu-linux.h:
Move GNU_LIBRARY_PENDING_OUTPUT_COUNT to configure.

* configure.ac (DATA_START, DATA_SEG_BITS): Move here from src/s.

* src/s/irix6-5.h (DATA_START, DATA_SEG_BITS):
* src/s/hpux10-20.h (DATA_SEG_BITS, DATA_START):
* src/s/gnu.h (DATA_START): Move definitions to configure.

(every file in Emacs that uses O_RDONLY already includes it; and this
does not seem like the problem a src/s file should be trying to solve).

(the included bsd-common.h does so)

This was added in 2012-01 in response to http://debbugs.gnu.org/10552 .
However, this issue had already been fixed in the trunk two years
earlier, by removing POSIX_SIGNALS altogether. Ref:

http://lists.gnu.org/archive/html/emacs-devel/2010-04/msg00002.html

* configure.in (SYSTEM_TYPE): New AC_DEFINE.

* msdos/sed2v2.inp (SYSTEM_TYPE): Set it.

* nt/config.nt (SYSTEM_TYPE): Define it.

* src/s/aix4-2.h, src/s/bsd-common.h, src/s/cygwin.h, src/s/darwin.h:
* src/s/gnu-kfreebsd.h, src/s/gnu-linux.h, src/s/gnu.h, src/s/hpux10-20.h:
* src/s/irix6-5.h, src/s/ms-w32.h, src/s/msdos.h, src/s/template.h:
* src/s/usg5-4-common.h: Remove SYSTEM_TYPE.

* configure.in: Remove all mention of src/m/*.
(machine, machfile, M_FILE, config_machfile, and_machfile): Remove.
All uses removed.
(BITS_PER_CHAR, BITS_PER_SHORT, BITS_PER_INT, BITS_PER_LONG)
(BITS_PER_LONG_LONG): Move to src/lisp.h.
* lib/makefile.w32-in: Remove dependencies on
$(EMACS_ROOT)/src/m/intel386.h.
* make-dist: Don't make links to src/m.
* admin/CPP-DEFINES: Do not mention src/m/*.h.
(BITS_PER_EMACS_INT, BITS_PER_LONG, BITS_PER_CHAR)
(BITS_PER_SHORT, BITS_PER_INT): Remove.
* admin/MAINTAINERS: Remove src/m/.
* lib-src/makefile.w32-in: Remove dependencies on
$(EMACS_ROOT)/src/m/intel386.h.
* msdos/mainmake.v2 (TAGS tags): Don't look at $(CURDIR)/src/m/intel386.h.
* nt/config.nt: Do not include "m/intel386.h"; file was removed.
(BITS_PER_CHAR, BITS_PER_SHORT, BITS_PER_INT, BITS_PER_LONG):
Move to src/lisp.h.
(EMACS_INT_MAX): New macro.
This directory predates autoconf and is no longer needed nowadays.
Move its few remaining bits of functionality to where they're needed.
* src/m/README, src/m/alpha.h, src/m/amdx86-64.h, src/m/ia64.h, src/m/ibmrs6000.h:
* src/m/ibms390x.h, src/m/intel386.h, src/m/m68k.h, src/m/macppc.h:
* src/m/sparc.h, src/m/template.h: Remove.
* src/Makefile.in (M_FILE): Remove.  All uses removed.
* src/alloc.c (POINTERS_MIGHT_HIDE_IN_OBJECTS):
* src/lisp.h (USE_LSB_TAG):
* src/mem-limits.h (EXCEEDS_LISP_PTR):
Use VAL_MAX, not VALBITS, in #if.
* src/lisp.h (EMACS_INT_MAX): New macro, useful in #if.
(EMACS_UINT): Define unconditionally now.
(BITS_PER_CHAR, BITS_PER_SHORT, BITS_PER_INT, BITS_PER_LONG)
(BITS_PER_EMACS_INT): New constants, replacing
what used to be in config.h, but not useful in #if.
(GCTYPEBITS, VALBITS): Define unconditionally, since m/* files don't
define them any more.
(VAL_MAX): New macro.
(VALMASK): Use it.
* src/puresize.h (PURESIZE_RATIO): Use EMACS_INT_MAX, not
BITS_PER_EMACS_INT, in #if.
* src/s/aix4-2.h (BROKEN_FIONREAD, BROKEN_SIGAIO, BROKEN_SIGPTY)
(BROKEN_SIGPOLL): Move here from m/ibmrs6000.h, which was removed.
* src/s/gnu-linux.h (ULIMIT_BREAK_VALUE) [__i386__]:
* src/s/ms-w32.h (DATA_START):
Move here from removed file m/intel386.h.
* src/s/gnu.h (NLIST_STRUCT): Remove undef; 'configure' does this.
* src/s/irix6-5.h (_LP64): Remove; lisp.h no longer needs this.

* lisp.h (GC_MARK_STACK): Default to GC_MAKE_GCPROS_NOOPS.
* s/cygwin.h, s/darwin.h, s/freebsd.h, s/gnu.h, s/irix6-5.h, s/msdos.h:
* s/netbsd.h, s/sol2-6.h:
Remove definition of GC_MARK_STACK, since the default now works.
* s/aix4-2.h, s/hpux10-20.h, s/unixware.h:
Define GC_MARK_STACK to GC_USE_GCPROS_AS_BEFORE, since that's
no longer the default.
* s/gnu-linux.h (GC_MARK_STACK): Adjust to change in default.

Fixes: debbugs:10552