Fix header including itself

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214146 91177308-0d34-0410-b5e6-96231b3b80d8
Fix typos / grammar.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214147 91177308-0d34-0410-b5e6-96231b3b80d8
Delete dead code.

It was added 12 years ago, but never used (and in the case of sort, never
implemented).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214150 91177308-0d34-0410-b5e6-96231b3b80d8