Summary:
This patch removes a private matcher in fuchsia/TrailingReturnType check because
the matcher is now in ASTMatchers
Reviewers: aaron.ballman, alexfh, hokein
Reviewed By: aaron.ballman
Subscribers: xazax.hun, cfe-commits
Differential Revision: https://reviews.llvm.org/D49618
llvm-svn: 337707