Explicitly cast away the const-ness instead of doing it implicitly.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173232 91177308-0d34-0410-b5e6-96231b3b80d8
Explicitly cast away the const-ness instead of doing it implicitly.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173241 91177308-0d34-0410-b5e6-96231b3b80d8