Report compile-time error when extending, mixing in or implementing a malformed type.

sdk/lib/_internal/compiler/implementation/warnings.dart

 // Copyright (c) 2011, 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 dart2js;
 
 const DONT_KNOW_HOW_TO_FIX = "";
 
 /**
  * The messages in this file should meet the following guide lines:
@@ skipping 695 matching lines @@
 
   static const MessageKind CLASS_NAME_EXPECTED = const MessageKind(
       "Error: Class name expected.");
 
   static const MessageKind CANNOT_EXTEND = const MessageKind(
       "Error: '#{type}' cannot be extended.");
 
   static const MessageKind CANNOT_IMPLEMENT = const MessageKind(
       "Error: '#{type}' cannot be implemented.");
 
+  static const MessageKind CANNOT_EXTEND_MALFORMED = const MessageKind(
+      "Error: A class can't extend a malformed type.",
+      howToFix: "Try correcting the malformed type annotation or removing the "
+        "'extends' clause.",
+      examples: const ["""
+class A extends Malformed {}
+main() => new A();"""]);
+
+  static const MessageKind CANNOT_IMPLEMENT_MALFORMED = const MessageKind(
+      "Error: A class can't implement a malformed type.",
+      howToFix: "Try correcting the malformed type annotation or removing the "
+        "type from the 'implements' clause.",
+      examples: const ["""
+class A implements Malformed {}
+main() => new A();"""]);
+
+  static const MessageKind CANNOT_MIXIN_MALFORMED = const MessageKind(
+      "Error: A class can't mixin a malformed type.",
+      howToFix: "Try correcting the malformed type annotation or removing the "
+        "type from the 'with' clause.",
+      examples: const ["""
+class A extends Object with Malformed {}
+main() => new A();"""]);
+
   static const MessageKind CANNOT_MIXIN = const MessageKind(
       "Error: The type '#{type}' can't be mixed in.",
       howToFix: "Try removing '#{type}' from the 'with' clause.",
       examples: const ["""
 class C extends Object with String {}
 
 main() => new C();
 """, """
 typedef C = Object with String;
 
@@ skipping 720 matching lines @@
 
 class CompileTimeConstantError extends Diagnostic {
   CompileTimeConstantError(MessageKind kind, Map arguments, bool terse)
     : super(kind, arguments, terse);
 }
 
 class CompilationError extends Diagnostic {
   CompilationError(MessageKind kind, Map arguments, bool terse)
     : super(kind, arguments, terse);
 }