[compiler-rt] [FMV][AArch64] Add initial AT_HWCAP3 / AT_HWCAP4 support (PR #161595)

[Alexandros Lamprineas via llvm-commits]

================
@@ -19,9 +18,14 @@ void CONSTRUCTOR_ATTRIBUTE __init_cpu_features(void) {
   if (res)
     return;
 
+  elf_aux_info(AT_HWCAP3, &hwcap3, sizeof hwcap3);
----------------
labrinea wrote:

Should this and the the call below be taken into account before we early exit above or not?

https://github.com/llvm/llvm-project/pull/161595