Fix comments.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192847 91177308-0d34-0410-b5e6-96231b3b80d8
Remove an old, seemingly out of date, comment.

The referenced script no longer seems to exist.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192848 91177308-0d34-0410-b5e6-96231b3b80d8
Add preprocessor support for powerpc vsx.

The test should be expanded upon for more powerpc checking.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@192849 91177308-0d34-0410-b5e6-96231b3b80d8