Use show rather than pshow on CompState.

CompState now contains Sets and Maps, which aren't instances of Data and thus
break pshow. This could be fixed in the future by providing instance
definitions, assuming the GHC library maintainers don't beat us to it.

Pass.hs

@@ -89,7 +89,7 @@ debugAST p
           veryDebug $ "}}}"
           veryDebug $ "{{{ State"
           ps <- get
-          veryDebug $ pshow ps
+          veryDebug $ show ps
           veryDebug $ "}}}"
 
 -- | Number lines in a piece of text.