[clang] Reapply "[Clang][Sema] Fix crash when 'this' is used in a dependent class scope function template specialization that instantiates to a static member function (#87541)" (PR #88311)

[Krystian Stasiowski via cfe-commits]

sdkrystian wrote:

The expression type need to be set to `ASTContext::DependentTy` (currently, it's set to `ASTContext::OverloadTy`) if we find a member of a base class (as it is for direct members). Should be an easy fix, so I'm thinking of not reverting and just opening a PR that will address this.

https://github.com/llvm/llvm-project/pull/88311