[compiler-rt] [llvm] [AIX] PGO codegen changes for function-sections. (PR #139761)

[Sean Fertile via llvm-commits]

mandlebug wrote:

@amy-kwan I had to rebase the patch to fix a merge conflict, and then clang-formated the test source since it was causing the formatting check to fail. Can you have a quick second look before I commit it?

https://github.com/llvm/llvm-project/pull/139761