ObjectiveC migrator. This patch infers readonly properties for no-parameter 
instance methods returning non-void. This will be quite noisy. So, it is 
placed under a new migrator flag -objcmt-migrate-readonly-property.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@189537 91177308-0d34-0410-b5e6-96231b3b80d8