Handle missing const constructor.

tests/language/missing_const_constructor_test.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.
+
+// Test handling of unknown constructor in const expression.
+
+class GoodClass {
+  const GoodClass();
+}
+
+GoodClass GOOD_CLASS
+    = const GoodClass() /// 01: ok
+    = const GoodClass.BAD_NAME() /// 02: compile-time error
+    = const GoodClass("bad arg") /// 03: compile-time error
+;
+
+
+const BadClass BAD_CLASS = const BadClass(); /// 04: compile-time error
+BadClass BAD_CLASS = const BadClass(); /// 05: compile-time error
+
+void main() {
+  try {
+    print(GOOD_CLASS);
+    print(BAD_CLASS); /// 04: continued
+    print(BAD_CLASS); /// 05: continued
+    print(const BadClass()); /// 06: compile-time error
+  } catch (e) {
+
+  }
+}