[PATCH v3] aarch64: add support for hwcap3,4

[Florian Weimer]

* enh:

> On Wed, Apr 23, 2025 at 11:41 AM Yury Khrustalev
>> And what about code that uses the __ifunc_arg_t struct name which
>> we'd delete in favour of the new resolver interface?
>
> why delete it? you can always keep that for backwards source
> compatibility. (as Android would.)

And this works because GCC does not perform type checking for IFUNC
resolver declarations.  Both approaches will work.

Thanks,
Florian