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

[Chen Zheng via cfe-commits]

chenzheng1030 wrote:

> Is it possible that we fix the hack implementation with some future version (I will open an issue and work on it afterwards)? How about let's move on with current approach?
> @amy-kwan @stephenpeckham @bzEq @chenzheng1030 Appreciate your comments. Thank you!

I am not against this proposal given the internal timeline.

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