[Compiler-rt] [Aarch64] Missing GCS property in assembly ( *.S) files

[kraj]

Compiler-rt's assembly files do not get the GCS properties when compiled with -mbranch=protection=standard with clang-21

dump of a object generated from .S file says

Properties: AArch64 feature: BTI, PAC

where as objects from .c files have

Properties: AArch64 feature: BTI, PAC, GCS

This causes shared objects linking with -rtlib=compiler-rt ends up with mssed GCS property as well. If we choose -rtlib=libgcc then the property gets into shared libraries correctly.

We need to implement GCS support into needed asm files in compiler-rt for aarch64

[kraj]

@DanielKristofKiss @john-brawn-arm @vhscampos FYI

[DanielKristofKiss]

Thanks, we will post a patch for this.