address some comments on r183474:
- factor the name construction part out from constructSetterName
- rename constructSetterName to the more appropriate constructSetterSelector

no functionality change intended.
rdar://problem/14035789

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183582 91177308-0d34-0410-b5e6-96231b3b80d8
7 files changed