Fix compilation with external LLVM

[wsmoses]

These patches probably should not be included if we're building with an external (likely modified LLVM).

[vtjnash]

You might still want this patch, though? Granted, I usually just turn them into a commit (or touch the .patch-applied file) so that I can work around them.

[vchuravy]

I did say folks who compile from svn life their life dangerously enough to also take the risk of loading multiple version of LLVM and having them clash

[JeffBezanson]

Should we merge this? It makes sense to me. If you're using svn you can apply patches manually as needed.