Fix a bug in nonfragile-abi2 when attempting to diagnose

previous use of a synthesized 'ivar' with property of same name
declared as @dynamic. In this case, 'ivar' is in the
inherited class and no diagnostics should be issued.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@111940 91177308-0d34-0410-b5e6-96231b3b80d8