Clean up the comments for this file now that its contents are totally
different from what the comments indicated. Also drop a no longer used
include that also violates the layering between Serialization and
Frontend.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@146230 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed