[clang] [CIR] Add PointerLikeType interface support for cir::PointerType (PR #139768)

[Erich Keane via cfe-commits]

https://github.com/erichkeane commented:

I am not a good reviewer for this, hopefully @razvanlupusoru  and @clementval can affirm this is right.

https://github.com/llvm/llvm-project/pull/139768