Revert "Fix assertion failures on annot_* tokens in clang -E"

This is causing a failure in the msan buildbot that I am having trouble
reproducing.  Reverting until I can figure out what went wrong.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@200492 91177308-0d34-0410-b5e6-96231b3b80d8