Make --enable-gcc-warnings a bit pickier, by also using -Wswitch.
* configure.ac (WERROR_CFLAGS): Don’t add -Wno-switch.
* lib-src/etags.c (main, consider_token, C_entries):
* src/coding.c (encode_invocation_designation):
* src/data.c (Ftype_of):
* src/eval.c (Fdefvaralias, default_toplevel_binding)
(Fbacktrace__locals, mark_specpdl):
* src/lisp.h (record_xmalloc):
* src/syntax.c (scan_lists, scan_sexps_forward):
* src/window.c (window_relative_x_coord):
* src/xdisp.c (push_it, pop_it):
* src/xterm.c (xg_scroll_callback, x_check_fullscreen):
Error out or do nothing (as appropriate) if a switch statement
with an enum value does not cover all of the enum.
* src/dispextern.h (struct iterator_stack_entry.u.comp):
Remove unused member discovered by using -Wswitch.
* src/lisp.h (record_xmalloc): Add a ‘+ 0’ to pacify -Wswitch.
* src/vm-limit.c (check_memory_limits):
Simplify warning-diagnostic computation by using a table.

Run admin/update-copyright.

* configure.ac (WERROR_CFLAGS): Don't disable -Wnested-externs.
While we're at it, don't disable -Wlogical-op either.
* src/bytecode.c: Include blockinput.h and keyboard.h rather
than rolling their APIs by hand.
* src/emacs.c: Include regex.h and rely on its and lisp.h's API
rather than rolling them by hand.
* src/lastfile.c: Include lisp.h, to check this file's API.
* src/lisp.h (lisp_eval_depth, my_edata, my_endbss, my_endbss_static):
New decls.
* src/regex.h (re_max_failures): New decl.
* src/unexcw.c, src/unexmacosx.c, src/unexw32.c:
Rely on lisp.h's API rather than rolling it by hand.
* src/vm-limit.c (__after_morecore_hook, __morecore, real_morecore):
Declare at top level, to pacify GCC -Wnested-externs.

 src/dosfns.c (dos_memory_info): New function.
 src/dosfns.h (dos_memory_info): Add prototype.
 src/alloc.c (Fmemory_info) [MSDOS]: Call dos_memory_info.
 src/vm-limit.c (get_lim_data) [MSDOS]: Call dos_memory_info, instead
 of doing some of its job.

The DATA_SEG_BITS hack was needed for older 32 bit platforms.
As a result of this change, Emacs won't work on IRIX 6.5 with IRIX
cc, but that platform is so old that SGI itself stopped supporting
it in December 2013.  If you still need Emacs on IRIX, please
either compile with GCC and port the undumping code, or run
'./configure --with-wide-int'.
* configure.ac (DATA_SEG_BITS): Remove.  All uses removed.
* src/alloc.c (gdb_make_enums_visible): Update to match lisp.h.
* src/lisp.h (GCTYPEBITS): Move definition up, and switch to the
DEFINE_GDB_SYMBOL_START way to define it.
(NONPOINTER_BITS): New macro.
(EMACS_INT): Use it.
[!USE_LSB_TAG && !WIDE_EMACS_INT]: Fail, and suggest reporting
the problem and/or configuring --with-wide-int.
(USE_LSB_TAG): Simplify, based on above changes.
(gdb_DATA_SEG_BITS): Remove.  All uses removed.
* src/vm-limit.c (exceeds_lisp_ptr): Remove.  All uses removed.

This is a followon simplification to the fix for Bug#13650.
* admin/CPP-DEFINES (DATA_START, ORDINARY_LINK): Remove.
* configure.ac (CRT_DIR, LIB_STANDARD, START_FILES, DATA_START)
(LD_FIRSTFLAG, ORDINARY_LINK, LIB_GCC): Remove.
(AC_CHECK_HEADERS_ONCE): Remove sys/resource.h, as it's
not always needed.
(HAVE_DATA_START): New macro.
* etc/PROBLEMS (LIBS_SYSTEM, LIBS_MACHINE, LIBS_STANDARD): Remove.
Remove legacy-systems section, as this stuff is no longer
applicable with current linking strategies.
* src/Makefile.in (LD_FIRSTFLAG, LIB_GCC, CRT_DIR, LIB_STANDARD)
(START_FILES): Remove.  All uses removed.
(otherobj): Remove $(VMLIMIT_OBJ), as it's now first.
(ALLOBJS): Move here from autodeps.mk, and with VMLIMITS_OBJ first.
(buildobj.h): Use it.
($(ALLOBJS)): Depend on globals.h.
(temacs$(EXEEXT)): Use $(ALLOBJS).
* src/autodeps.mk (ALLOBJS): Move to Makefile.in.
* src/deps.mk (vm-limit.o):
* src/makefile.w32-in ($(BLD)/vm-limit.$(O)):
Do not depend on mem-limits.h.
* src/emacs.c (__do_global_ctors, __do_global_ctors_aux)
(__do_global_dtors, __CTOR_LIST__, __DTOR_LIST__)
[__GNUC__ && !ORDINARY_LINK]: Remove.
* src/mem-limits.h, src/pre-crt0.c: Remove.
* src/unexaix.c, src/unexcoff.c: Don't include mem-limits.h.
* src/unexcoff.c (etext): New decl.
(make_hdr): Use it instead of start_of_data.
* src/vm-limit.c: Move most of mem-limits.h's contents here.
(data_start): New decl.  It's OK if this is approximate,
so simplify-away some unnecessary exactness.
(POINTER): Remove; all uses removed.
(data_space_start): Now char *, to avoid casts.
(exceeds_lisp_ptr): New function, replacing the old
EXCEEDS_LISP_PTR macro.  All uses changed.
(check_memory_limits): Simplify and remove casts.
(start_of_data) [!CANNOT_DUMP || !SYSTEM_MALLOC]: Remove.
(memory_warnings): Use data_start instead of start_of_data.

Fixes: debbugs:13783

* ralloc.c (SIZE, POINTER, NIL):
* vm-limit.c (POINTER):
Remove, replacing all uses with C89 equivalents.  These old
symbols were present only for porting to pre-C89 platforms.