[llvm] [PowerPC] Handle CALL_RM like CALL for 32-bit ELF (PR #72758)

[Chen Zheng via llvm-commits]

https://github.com/chenzheng1030 approved this pull request.

LGTM as long as @ecnelises's comment about the LIT case is addressed.

https://github.com/llvm/llvm-project/pull/72758