ObjectiveC. Remove warning on mismatched methods
which may belong to unrelated classes. It was
primarily intended for miuse of @selector expression.
But warning is too noisy and will be issued when
an actual @selector is used. // rdar://15740134


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@198952 91177308-0d34-0410-b5e6-96231b3b80d8