Revert "cps-ir: Support foreign code."

pkg/compiler/lib/src/types/type_mask.dart

Index: pkg/compiler/lib/src/types/type_mask.dart
diff --git a/pkg/compiler/lib/src/types/type_mask.dart b/pkg/compiler/lib/src/types/type_mask.dart
index 8e4e2d22ce07c0caceb80b7b93587592d33aaf27..0c032f673b448bd86b5b6e3e03882390b0fb8a8f 100644
--- a/pkg/compiler/lib/src/types/type_mask.dart
+++ b/pkg/compiler/lib/src/types/type_mask.dart
@@ -22,8 +22,8 @@ abstract class TypeMask {
 
   factory TypeMask.exact(ClassElement base, ClassWorld classWorld) {
     assert(invariant(base, classWorld.isInstantiated(base),
-        message: "Cannot create extact type mask for uninstantiated class "
-          "${base.name}"));
+        message: "Cannot create extact type mask for "
+                 "uninstantiated class $base"));
     return new FlatTypeMask.exact(base);
   }