[llvm] [PowerPC] support tail call optimization on AIX tail call (PR #161690)

[zhijian lin via llvm-commits]

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diggerlin wrote:

talked with Hubert offline, he told me that the alignment attribute on a parameter is actually ignored though (i.e., you can observe that the parameter object is not aligned). @hubert-reinterpretcast , so we do not need to worry about it the `undef` with "The alignment has to match"

https://github.com/llvm/llvm-project/pull/161690