Consolidating several table-generated files containing parser-related string switches into a single file. This reduces build-related complexity by replacing four separate projects (and table-gen instantiations) with a single one.

No functional changes intended.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@200424 91177308-0d34-0410-b5e6-96231b3b80d8