[clang-tools-extra] [clang][include-cleaner] Support ObjC @selector expressions in WalkAST (PR #212564)

[via cfe-commits]

dmaclach wrote:

@kadircet @nico Could one or more of you fine gents take a look at this when you have a moment? I believe it should only impact Objective-C code at this time, and Objecitve-C is disabled for include-cleaner at this moment.

https://github.com/llvm/llvm-project/pull/212564