[clang] [clang-tools-extra] [lldb] Reland: [clang] preserve class type sugar when taking pointer to member (PR #132401)

[Matheus Izvekov via cfe-commits]

mizvekov wrote:

In one of these changes we did bump one of these bit fields down to 15 bits, starting from 16.

https://github.com/llvm/llvm-project/pull/132401