Move Sema::PropertyIfSetterOrGetter to ObjCMethodDecl::findPropertyDecl.

Then, switch users of PropertyIfSetterOrGetter and LookupPropertyDecl
(the latter by name) over to findPropertyDecl. This actually makes
-Wreceiver-is-weak a bit stronger than it was before.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@165628 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed