Store the warning option corresponding to a diagnostics as an index into the option table instead of storing the name.

Another 8 bytes + relocation removed from every diagnostic on x86_64.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@150615 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed