Prefer stdbit.h to count-one-bits.h etc

C23's <stdbit.h> in the long run should be better supported than
Gnulib's count-one-bits.h and similar headers, so switch to the
C23 primitives, with a Gnulib fallback for platforms lacking C23.
* admin/merge-gnulib (GNULIB_MODULES): Remove count-leading-zeros,
count-one-bits, count-trailing-zeros.  Add stdc_bit_width,
stdc_count_ones, stdc_trailing_zeros.
* lib/count-leading-zeros.c, lib/count-leading-zeros.h:
* lib/count-one-bits.c, lib/count-one-bits.h:
* lib/count-trailing-zeros.c, lib/count-trailing-zeros.h: Remove.
* lib/stdbit.c, lib/stdbit.in.h, lib/stdc_bit_width.c:
* lib/stdc_count_ones.c, lib/stdc_leading_zeros.c:
* lib/stdc_trailing_zeros.c, m4/stdbit_h.m4:
New files, copied from Gnulib.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* src/data.c: Do not include count-one-bits.h, count-trailing-zeros.h.
Instead, rely on lisp.h including stdbit.h.
(Flogcount, Fbool_vector_count_population)
(Fbool_vector_count_consecutive): Use stdbit.h macros instead of
count-one-bits.h and count-trailing-zeros.h macros.
(shift_right_ull, count_one_bits_word, pre_value)
(count_trailing_zero_bits): Remove; no longer needed.
* src/lisp.h: Include stdbit.h instead of count-leading-zeros.h.
(elogb): Use stdbit.h macro instead of count-leading-zeros.h macro.

1 files changed, 3 insertions, 2 deletions

diff --git a/admin/merge-gnulib b/admin/merge-gnulib
index c4daaded015..65e098c7123 100755
--- a/admin/merge-gnulib
+++ b/admin/merge-gnulib
@@ -29,7 +29,6 @@ GNULIB_MODULES='
   alignasof alloca-opt binary-io boot-time byteswap c-ctype c-strcase
   canonicalize-lgpl
   careadlinkat close-stream copy-file-range
-  count-leading-zeros count-one-bits count-trailing-zeros
   crypto/md5 crypto/md5-buffer
   crypto/sha1-buffer crypto/sha256-buffer crypto/sha512-buffer
   d-type diffseq double-slash-root dtoastr dtotimespec dup2
@@ -44,7 +43,9 @@ GNULIB_MODULES='
   nanosleep nproc nstrftime
   pathmax pipe2 pselect pthread_sigmask
   qcopy-acl readlink readlinkat regex
-  sig2str sigdescr_np socklen stat-time std-gnu11 stdbool stdckdint stddef stdio
+  sig2str sigdescr_np socklen stat-time std-gnu11 stdbool
+  stdc_bit_width stdc_count_ones stdc_trailing_zeros
+  stdckdint stddef stdio
   stpcpy strnlen strnlen strtoimax symlink sys_stat sys_time
   tempname time-h time_r time_rz timegm timer-time timespec-add timespec-sub
   update-copyright unlocked-io utimensat