Use gcc __builtin_stdc_* builtins in stdbit.h if possible

The following patch uses the GCC 14 __builtin_stdc_* builtins in stdbit.h
for the type-generic macros, so that when compiled with GCC 14 or later,
it supports not just 8/16/32/64-bit unsigned integers, but also 128-bit
(if target supports them) and unsigned _BitInt (any supported precision).
And so that the macros don't expand arguments multiple times and can be
evaluated in constant expressions.

The new testcase is gcc's gcc/testsuite/gcc.dg/builtin-stdc-bit-1.c
adjusted to test stdbit.h and the type-generic macros in there instead
of the builtins and adjusted to use glibc test framework rather than
gcc style tests with __builtin_abort ().

Signed-off-by: Jakub Jelinek <jakub@redhat.com>
Reviewed-by: Joseph Myers <josmyers@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/stdlib/Makefile b/stdlib/Makefile
index d587f054d1..9898cc5d8a 100644
--- a/stdlib/Makefile
+++ b/stdlib/Makefile
@@ -308,6 +308,7 @@ tests := \
   tst-setcontext10 \
   tst-setcontext11 \
   tst-stdbit-Wconversion \
+  tst-stdbit-builtins \
   tst-stdc_bit_ceil \
   tst-stdc_bit_floor \
   tst-stdc_bit_width \