fixes the poly problem with 2.11.0-M8

Would it be possible for you to look into c.macroApplication.tpe and then figure out the type argument for caseUniv? (sorry, I couldn't figure out an answer myself from a cursory look at what's going on). 

If yes, then going for it would fix the poly issues. If no, then just typechecking against c.macroApplication.tpe (as proposed by the pull request) would also provide a fix.