Remove unused includes and out of date comment. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224413 91177308-0d34-0410-b5e6-96231b3b80d8
Remove a debugging assert.

Sorry for the noise, I have no idea how it survived to the final version.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224414 91177308-0d34-0410-b5e6-96231b3b80d8