aarch64: PR target/115475 Implement missing __ARM_FEATURE_SVE_BF16 macro
The ACLE requires __ARM_FEATURE_SVE_BF16 to be enabled when SVE and BF16
and the associated intrinsics are available.
GCC does support the required intrinsics for TARGET_SVE_BF16 so define
this macro too.
Bootstrapped and tested on aarch64-none-linux-gnu.
gcc/
PR target/115475
* config/aarch64/aarch64-c.cc (aarch64_update_cpp_builtins):
Define __ARM_FEATURE_SVE_BF16 for TARGET_SVE_BF16.
gcc/testsuite/
PR target/115475
* gcc.target/aarch64/acle/bf16_sve_feature.c: New test.
Signed-off-by: Kyrylo Tkachov <ktkachov@nvidia.com>