FindGTK2: Search homebrew paths for arch-specific headers
Without this, CMake fails to find brew-installed GTK2 on macOS. With it, GTK2 is found.
Topic-rename: FindGTK2-homebrew
Edited by Brad King
Without this, CMake fails to find brew-installed GTK2 on macOS. With it, GTK2 is found.
Topic-rename: FindGTK2-homebrew