Cleanup objc's gc attributes code no longer needed.
This make warn-weak-field.m to fail (subject of
a followup patch). 
attr-objc-gc.m no passes.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64925 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed