Make LookUpIdentifierInfo const. This makes the Identifiers table mutable and is
a little fuzzy, but conceptually it's just uniquing the identifier.

Chris, please review. I debated splitting into const/non-const versions where
the const one propogated constness to the resulting IdentifierInfo*.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@86106 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed