Avoid creating invalid TypeMask.nonNullExact

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

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of types;
 
 /// An implementation of a [UniverseSelectorConstraints] that is consists if an only
 /// increasing set of [TypeMask]s, that is, once a mask is added it cannot be
 /// removed.
 class IncreasingTypeMaskSet extends UniverseSelectorConstraints {
@@ skipping 104 matching lines @@
     } else {
       return new TypeMask.exactOrEmpty(base, classWorld);
     }
   }
 
   const factory TypeMask.nonNullEmpty() = FlatTypeMask.nonNullEmpty;
 
   factory TypeMask.nonNullExact(ClassElement base, ClassWorld classWorld) {
     assert(invariant(base, classWorld.isInstantiated(base),
         message: () => "Cannot create exact type mask for "
-                 "uninstantiated class $base.\n${classWorld.dump()}"));
+                 "uninstantiated class $base.\n${classWorld.dump(base)}"));
     return new FlatTypeMask.nonNullExact(base);
   }
 
   factory TypeMask.nonNullExactOrEmpty(ClassElement base,
       ClassWorld classWorld) {
     if (classWorld.isInstantiated(base)) {
       return new FlatTypeMask.nonNullExact(base);
     }
     return const TypeMask.nonNullEmpty();
   }
@@ skipping 194 matching lines @@
   /**
    * Returns the [element] that is known to always be hit at runtime
    * on this mask. Returns null if there is none.
    */
   // TODO(johnniwinther): Move this method to [World].
   Element locateSingleElement(
       Selector selector,
       TypeMask mask,
       Compiler compiler);
 }