removing code duplication in RecursiveASTVisitor.h

Hi,

I uploaded a patch to http://codereview.appspot.com/1653043 to avoid
repeating the lists of operators twice in RecursiveASTVisitor.h. This
should make the code easier to maintain, but we no longer need to
worry about the duplicates going out of sync. What do you think?

Chandler and I discussed the option of generating the list from a .td
file. I'm fine with that idea, but prefer to wait for the list to be
needed at another place before doing that. Thoughts? Thanks,

I’ve committed this as r105796. We can factor these out to tablegen files if there is a desire to do so in a subsequent patch.