[clang] [clang-repl] Use canonical types in QualTypeToString (PR #190528)

[Harald van Dijk via cfe-commits]

hvdijk wrote:

Personally, I think it's best to have the reverts as part of this PR (which also means squashing it into one commit when merging) so that we can easily see that tests are the same as before, but I don't mind if other people feel it's better to have them separate.

https://github.com/llvm/llvm-project/pull/190528