[clang] [clang][ASTMatcher] Add matchers for isExplicitObjectMemberFunction() (PR #84446)

[Balazs Benics via cfe-commits]

steakhal wrote:

I had to push a fixup commit, because I forgot about one switch-case. https://github.com/llvm/llvm-project/commit/f07157eb2e8212068cb9469d77f9bc3779ef2ea4
I pushed it already to fix the build bot, but let me know if you disagree with the fix.

https://github.com/llvm/llvm-project/pull/84446