[llvm] [SFrames] Implement .cfi_restore, remember_state, and restore_state (PR #159832)

[via llvm-commits]

Sterling-Augustine wrote:

The build failures here are unrelated:

4 tests failed
Failed Tests
(click on a test name to see its output)

Clang
Clang.CodeGen/PowerPC/builtins-ppc-p7.c
Clang.CodeGen/PowerPC/builtins-ppc-xlcompat-macros.c
Clang.CodeGen/PowerPC/ppc-x86gprintrin.c
Clang.CodeGen/PowerPC/ppc-xmmintrin.c

https://github.com/llvm/llvm-project/pull/159832