Mid-air collision. reapply r173656.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173661 91177308-0d34-0410-b5e6-96231b3b80d8
Refactor ObjCARCAliasAnalysis into its own file.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173662 91177308-0d34-0410-b5e6-96231b3b80d8
Cleaned up includes in various ObjCARC files and removed some whitespace violations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173663 91177308-0d34-0410-b5e6-96231b3b80d8