[PATCH] [IPO] enable EP_EnabledOnOptLevel0 passes for OptLevel > 0

[Chandler Carruth]

  The stated explanation doesn't really make a lot of sense for the change. Why not fix them to be added to the correct pass manager? What's really going on here?

  Also, is there any way to unittest this so we don't regress? It seems like it should be easy to rig up dummy passes, build a pass manager and run it over an empty module and ensure that the correct set of passes was initialized...

http://llvm-reviews.chandlerc.com/D237