Re-sort #include lines using the llvm/utils/sort_includes.py script.

Removes a duplicate #include as well as cleaning up some sort order
regressions since I last ran the script over Clang.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@171364 91177308-0d34-0410-b5e6-96231b3b80d8