Run "TZ=UTC0 admin/update-copyright".

* src/image.c (native_image_type): Declare static.
* src/keyboard.c (lispy_function_keys): Declare static on NS.
* src/nsmenu.m (context_menu_value):
* src/nsterm.m (ns_frame_parm_handlers): Move extern declarations...
* src/nsterm.h: ...here.
* test/src/emacs-module-resources/mod-test.c: Add extern declaration.

Be more systematic about putting space before paren in calls,
and in avoiding unnecessary parentheses in macros.
This was partly inspired by my wading through gcc -E output
while debugging something else, and seeing too many parens.

This patch does not change the generated .o files on my platform.

C23 is adding the C++ keywords bool, true, and false;
prefer them to <stdbool.h> if they are available.
* admin/merge-gnulib (GNULIB_MODULES):
Add stdbool, which emulates C23 on pre-C23 platforms.
(AVOIDED_MODULES): Remove stdbool; Gnulib has renamed
this module to stdbool-c99 and nobody uses it so it does
not need to be avoided.
* m4/c-bool.m4: New file, from Gnulib stdbool module.
* lib-src/seccomp-filter.c, src/conf_post.h, src/dynlib.h:
* src/emacs-module.c, src/nsterm.m, src/systhread.h:
* test/src/emacs-module-resources/mod-test.c:
Use the C23 style and use bool without including <stdbool.h>.
The Gnulib stdbool module causes config.h to include stdbool.h
on pre-C23 platforms.
* src/emacs-module.h.in:
Don’t include <stdbool.h> if C23 or later, or if
it has already been included.

mod-test.c should not use Gnulib code, as that creates
unnecessary coupling between Emacs internals and this test module.
Also Gnulib code is compiled without -fPIC whereas mod-test.c
needs -fPIC and recompiling Gnulib with -fPIC would be too painful.
* src/Makefile.in (LIB_NANOSLEEP): New macro.
(LIBES): Use it.
* test/Makefile.in (REPLACE_FREE, FREE_SOURCE_0, FREE_SOURCE_0):
Remove.  All uses removed.
(LIB_CLOCK_GETTIME, LIB_NANOSLEEP): New macros.
(MODULE_CFLAGS): Do not -I from lib as that would include Gnulib
modifications to standard .h files (e.g., "#define nanosleep
rpl_nanosleep") and we don’t want the Gnulib replacements.
Instead, for gmp.h (on platforms lacking <gmp.h>) simply '-I.'
with a suitable gmp.h.
(gmp.h): New rule to create a suitable gmp.h.
($(test_module)): Depend on config.h since the code uses config.h.
Depend on gmp.h if we need to create a suitable one.
If compiling mini-gmp.h, compile the original one and not
the Emacs-specific one, to lessen coupling with Emacs internals.
Link with LIB_CLOCK_GETTIME and LIB_NANOSLEEP.
(clean): Remove gmp.h.
* test/src/emacs-module-resources/mod-test.c: Don’t include timespec.h.
All uses of timespec.h APIs changed to use system-supplied APIs.
Change _Static_assert to plain assert, so that we needn’t rely
on Gnulib’s _Static_assert.
(timespec_le) [CLOCK_REALTIME]: New function.
Change use of timespec_cmp changed to use this instead.
(Fmod_test_sleep_until, Fmod_test_nanoseconds):
Define these functions and their Lisp names mod-test-sleep-until
and mod-test-nanoseconds only if CLOCK_REALTIME,
since they now won’t work on platforms lacking CLOCK_REALTIME.
(Fmod_test_nanoseconds): Just use _Static_assert since it
should work on all platforms.
* test/src/emacs-module-tests.el (mod-test-sleep-until)
(mod-test-nanoseconds, mod-test-double):
Skip test if the corresponding functione is not defined.

* test/src/emacs-module-resources/mod-test.c (Fmod_test_userptr_make):
Don’t dump core if calloc returns null and signal_errno returns.

* oldXMenu/Create.c (XMenuCreate):
* oldXMenu/Internal.c (_XMRecomputePane, _XMRecomputeSelection):
* oldXMenu/XMakeAssoc.c (XMakeAssoc):
* test/src/emacs-module-resources/mod-test.c (Fmod_test_userptr_make):
Don’t assume that malloc and calloc succeed.