[PATCH] aarch64: make GCS configure checks aarch64-only

[Yury Khrustalev]

On Mon, Nov 24, 2025 at 12:45:12PM +0000, Yury Khrustalev wrote:
> We only need to enable GCS tests on AArch64 targets, however previously
> the configure checks for GCS support in compiler and linker were added
> for all targets which was not efficient.
> 
> To enable tests for GCS we need 4 things to be true:
> 
>  - Compiler supports GCS branch protection.
>  - Test compiler supports GCS branch protection.
>  - Linker supports GCS marking of binaries.
>  - The CRT objects provided by the toolchain have GCS marking.
> 
> To check for the latter, we add new macro to aclocal.m4 that allows to
> grep output from readelf.
> 
> We check all four and then put the result in one make variable to
> simplify checks in makefiles.
> 
> ---
> 
> Passes regression in AArch64. OK for trunk?
> Base commit: 0f7b73f2ed
> 
> ---
>  aclocal.m4                               |  15 +++
>  configure                                |  98 ------------------
>  configure.ac                             |  17 ----
>  sysdeps/aarch64/configure                | 124 +++++++++++++++++++++++
>  sysdeps/aarch64/configure.ac             |  32 ++++++
>  sysdeps/unix/sysv/linux/aarch64/Makefile |   4 +-
>  6 files changed, 173 insertions(+), 117 deletions(-)

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