Be sure to check ARC conventions on the implicit method declarations
of a property just in case the property's getter happens to be +1.
We won't synthesize a getter for such a property, but we will allow
the user to define a +1 method for it.
rdar://13115896

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178731 91177308-0d34-0410-b5e6-96231b3b80d8