[PATCH 5/15] arm: Implement target feature macros for PACBTI
This patch implements target feature macros when PACBTI is enabled
through the -march option or -mbranch-protection. The target feature
macros __ARM_FEATURE_PAC_DEFAULT and __ARM_FEATURE_BTI_DEFAULT are
specified in ARM ACLE
<https://developer.arm.com/documentation/101028/0012/5--Feature-test-macros?lang=en>
__ARM_FEATURE_PAUTH and __ARM_FEATURE_BTI are specified in the
pull-request <https://github.com/ARM-software/acle/pull/55>.
Approved here
<https://gcc.gnu.org/pipermail/gcc-patches/2021-December/586334.html>.
gcc/
* config/arm/arm-c.c (arm_cpu_builtins): Define
__ARM_FEATURE_BTI_DEFAULT, __ARM_FEATURE_PAC_DEFAULT,
__ARM_FEATURE_PAUTH and __ARM_FEATURE_BTI.