stdbit-h, stdc_*: New modules, part of the stdbit module.

* lib/stdbit.in.h (_GL_STDC_*_INLINE): New macros.
Enclose function definitions in #if @GL_STDC_*@ conditionals.
* lib/stdc_leading_zeros.c: New file.
* lib/stdc_leading_ones.c: New file.
* lib/stdc_trailing_zeros.c: New file.
* lib/stdc_trailing_ones.c: New file.
* lib/stdc_first_leading_zero.c: New file.
* lib/stdc_first_leading_one.c: New file.
* lib/stdc_first_trailing_zero.c: New file.
* lib/stdc_first_trailing_one.c: New file.
* lib/stdc_count_zeros.c: New file.
* lib/stdc_count_ones.c: New file, based on lib/stdbit.c.
* lib/stdc_has_single_bit.c: New file.
* lib/stdc_bit_width.c: New file.
* lib/stdc_bit_floor.c: New file.
* lib/stdc_bit_ceil.c: New file.
* lib/stdbit.c (__gl_stdbit_popcount_support): Remove variable.
* m4/stdbit_h.m4 (gl_STDBIT_H): Initialize GL_STDC_* variables.
* modules/stdbit-h: New file, based on modules/stdbit.
(Depends-on): Add gen-header.
(Makefile.am): Substitute GL_STDC_* variables.
* modules/stdc_leading_zeros: New file.
* modules/stdc_leading_ones: New file.
* modules/stdc_trailing_zeros: New file.
* modules/stdc_trailing_ones: New file.
* modules/stdc_first_leading_zero: New file.
* modules/stdc_first_leading_one: New file.
* modules/stdc_first_trailing_zero: New file.
* modules/stdc_first_trailing_one: New file.
* modules/stdc_count_zeros: New file.
* modules/stdc_count_ones: New file.
* modules/stdc_has_single_bit: New file.
* modules/stdc_bit_width: New file.
* modules/stdc_bit_floor: New file.
* modules/stdc_bit_ceil: New file.
* modules/stdbit: Change to a pure composition module.
* modules/stdc_leading_zeros-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_leading_ones-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_trailing_zeros-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_trailing_ones-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_first_leading_zero-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_first_leading_one-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_first_trailing_zero-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_first_trailing_one-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_count_zeros-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_count_ones-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_has_single_bit-tests: New file, based on
modules/stdbit-tests.
* modules/stdc_bit_width-tests: New file, based on modules/stdbit-tests.
* modules/stdc_bit_floor-tests: New file, based on modules/stdbit-tests.
* modules/stdc_bit_ceil-tests: New file, based on modules/stdbit-tests.
* modules/stdbit-tests: Remove file.
* doc/posix-functions/stdc_leading_zeros.texi: Update.
* doc/posix-functions/stdc_leading_ones.texi: Likewise.
* doc/posix-functions/stdc_trailing_zeros.texi: Likewise.
* doc/posix-functions/stdc_trailing_ones.texi: Likewise.
* doc/posix-functions/stdc_first_leading_zero.texi: Likewise.
* doc/posix-functions/stdc_first_leading_one.texi: Likewise.
* doc/posix-functions/stdc_first_trailing_zero.texi: Likewise.
* doc/posix-functions/stdc_first_trailing_one.texi: Likewise.
* doc/posix-functions/stdc_count_zeros.texi: Likewise.
* doc/posix-functions/stdc_count_ones.texi: Likewise.
* doc/posix-functions/stdc_has_single_bit.texi: Likewise.
* doc/posix-functions/stdc_bit_width.texi: Likewise.
* doc/posix-functions/stdc_bit_floor.texi: Likewise.
* doc/posix-functions/stdc_bit_ceil.texi: Likewise.

modules/stdc_first_trailing_zero-tests

@@ -0,0 +1,19 @@
+Files:
+tests/from-glibc/tst-stdc_first_trailing_zero.c
+tests/from-glibc/tst-stdbit.h
+tests/from-glibc/support/test-driver.c
+tests/macros.h
+
+Depends-on:
+libc-config
+stdbool
+stdint
+assert-h
+
+configure.ac:
+
+Makefile.am:
+TESTS += test-stdc_first_trailing_zero
+check_PROGRAMS += test-stdc_first_trailing_zero
+test_stdc_first_trailing_zero_SOURCES = from-glibc/tst-stdc_first_trailing_zero.c
+test_stdc_first_trailing_zero_CPPFLAGS = $(AM_CPPFLAGS) -I$(srcdir)/from-glibc -DGNULIB_TEST_STDBIT