Objective-C [qoi]. If property is going to be implemented
in the super class, do not issue the warning about property
in current class's protocol will not be auto synthesized.
// rdar://18179833


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@216769 91177308-0d34-0410-b5e6-96231b3b80d8