objc: Do not warn about mismatch on Super's readonly property attribute, 
related to a readwrite property, and
Sub's readwrite property. // rdar://9396329


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@141497 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed