[llvm] [PowerPC] Support local-dynamic TLS relocation on AIX (PR #66316)

[Chen Zheng via llvm-commits]

https://github.com/chenzheng1030 commented:

Some comments may need follow up, so I posted them first. I will continue to review the code generation part.

We need a front end patch to eliminate the error report in `clang/lib/Frontend/CompilerInvocation.cpp` and `clang/lib/Sema/SemaDeclAttr.cpp`, right?

https://github.com/llvm/llvm-project/pull/66316