Generate dynamic type errors according to spec.

runtime/vm/class_finalizer.h

 // Copyright (c) 2012, 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.
 
 #ifndef VM_CLASS_FINALIZER_H_
 #define VM_CLASS_FINALIZER_H_
 
 #include "vm/allocation.h"
 #include "vm/growable_array.h"
 
@@ skipping 42 matching lines @@
   };
 
   // Finalize given type while parsing class cls.
   // Also canonicalize type if applicable.
   static RawAbstractType* FinalizeType(const Class& cls,
                                        const AbstractType& type,
                                        FinalizationKind finalization);
 
   // Replace the malformed type with Dynamic and, depending on the given type
   // finalization mode and execution mode, mark the type as malformed or report
-  // a compile time error.
-  static void FinalizeMalformedType(const Class& cls,
+  // a compile time error. Prepend prev_error if not null.
+  static void FinalizeMalformedType(const Error& prev_error,
+                                    const Class& cls,
                                     const Type& type,
                                     FinalizationKind finalization,
                                     const char* format, ...);
 
   // Pending classes are classes that need to be finalized.
   static void AddPendingClasses(const GrowableArray<const Class*>& classes);
 
   // Return false if we still have classes pending to be finalized.
   static bool AllClassesFinalized();
 
@@ skipping 40 matching lines @@
   static void ReportError(const Error& error);
   static void ReportError(const Script& script,
                           intptr_t token_index,
                           const char* format, ...);
   static void ReportError(const char* format, ...);
 };
 
 }  // namespace dart
 
 #endif  // VM_CLASS_FINALIZER_H_