[llvm] [AArch64] Added feature dependencies for SME2p1 to TargetParser (PR #81860)

[via llvm-commits]

CarolineConcatto wrote:

Can it have a test for  the sve types. Something like:
```
// RUN: %clang_cc1 -fclang-abi-compat=latest -triple aarch64-none-linux-gnu -target-feature +sme2p1  -S -disable-O0-optnone -Werror -Wall -emit-llvm -o - %s | opt -S -p mem2reg,instcombine,tailcallelim | FileCheck %s
// RUN: %clang_cc1 -fclang-abi-compat=latest -triple aarch64-none-linux-gnu -target-feature +sme2p1 -S -disable-O0-optnone -Werror -Wall -o /dev/null %s

#include <arm_sme.h>
svuint8_t foo(svuint8_t a)  {
   return a;
}
svfloat16x2_t foo(svuint16x2_t a)  {
   return a;
}
```

https://github.com/llvm/llvm-project/pull/81860