[clang] [clang-tools-extra] Reland: [clang] NFC: Clear some uses of MemberPointerType::getClass (PR #132317)

[Matheus Izvekov via cfe-commits]

mizvekov wrote:

@alexfh @rupprecht thanks, that was indeed a separate regression, and this will be fixed here: https://github.com/llvm/llvm-project/pull/133113

https://github.com/llvm/llvm-project/pull/132317