[compiler-rt] [Compiler-rt] Add AArch64 routines for __arm_agnostic("sme_za_state") (PR #120059)

[Nico Weber via llvm-commits]

nico wrote:

This broke our our chromium/android build: https://issues.chromium.org/issues/385758019

```
[124576/130655] SOLINK ./libcapture_unittests__library.so
python3 ../../build/toolchain/gcc_solink_wrapper.py --readelf=../../third_party/llvm-build/Release+Asserts/bin/llvm-readelf --nm=../../third_p...(too long)
ld.lld: error: undefined symbol: __arm_tpidr2_save
>>> referenced by rotate_sme.cc:32 (../../third_party/libyuv/source/rotate_sme.cc:32)
>>>               libyuv_sme/rotate_sme.o:(TransposeWxH_SME) in archive obj/third_party/libyuv/libyuv_sme.a
>>> referenced by rotate_sme.cc:101 (../../third_party/libyuv/source/rotate_sme.cc:101)
>>>               libyuv_sme/rotate_sme.o:(TransposeUVWxH_SME) in archive obj/third_party/libyuv/libyuv_sme.a
clang++: error: linker command failed with exit code 1 (use -v to see invocation)
```

Is that expected? Are we holding something wrong? Or is that too little information to say something useful?

https://github.com/llvm/llvm-project/pull/120059