Disabled the pass that checks for unused variables for now as it runs too slowly

checks/Check.hs

@@ -571,5 +571,5 @@ checkUnusedVar = forAnyASTStructBottomUpAccum doSpec
                when (not $ A.nameName name `elem` map A.nameName usedNames) $
                 do warnPC mspec WarnUnusedVariable $ formatCode "Unused variable: %" name
                    modify (\st -> st { csNames = Map.delete (A.nameName name) (csNames st) })
-                   substitute scope
+                   -- substitute scope
     doSpec _ = return ()

pass/PassList.hs

@@ -68,8 +68,8 @@ commonPasses opts = concat $
   , enablePassesWhen csUsageChecking
      [abbrevCheckPass]
   , backendPasses
---  , [pass "Removing unused variables" [] []
---      (passOnlyOnAST "checkUnusedVar" (runChecks checkUnusedVar))]
+  , [pass "Removing unused variables" [] []
+      (passOnlyOnAST "checkUnusedVar" (runChecks checkUnusedVar))]
   ]
 
 filterPasses :: CompState -> [Pass t] -> [Pass t]