General cleanups.

* Remove dead methods.
* Use the 'operator==' method instead of 'contains', which isn't needed.
* Fix some comments.

No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171523 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed