[compiler-rt] [AIX][PGO] Handle atexit functions when dlclose'ing shared libraries (PR #102940)

[Wael Yehia via llvm-commits]

w2yehia wrote:

Hi @mtrofin @ellishg @MaskRay @evodius96 @xur-llvm 
the clang-format failure is due to one line that I think is better kept as-is,
other than that the PR is ready. 
I would appreciate if someone can take a look at the fix, and comment if we want it enabled for netbsd.
Thanks

https://github.com/llvm/llvm-project/pull/102940