aarch64: Backporting a fix related to a change in the kernel

[Yury Khrustalev]

Hi everyone,

There is a change proposed for the kernel [1] for which there should be
a corresponding update in Glibc. Corresponding ABI spec clarification can
be found in [2]. In a nutshell, to avoid incorrect SME state, both setjmp
and longjmp should clear SME ZA state. Currently, this is done in longjmp
already (it calls __libc_arm_za_disable) and a similar thing should occur
in setjmp.

Question: when the kernel patch [1] is accepted and released, is it okay
to submit Glibc change and backport it into the recent releases (as soon
as accepted into master)? The change will affect:

  sysdeps/aarch64/setjmp.S

[1]: https://lore.kernel.org/linux-arm-kernel/20250417190113.3778111-1-mark.rutland@arm.com/
[2]: https://github.com/ARM-software/abi-aa/pull/325

Kind regards,
Yury