Handle const loop variable.

pkg/compiler/lib/src/diagnostics/messages.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.
 
 
 /**
  * The messages in this file should meet the following guide lines:
  *
  * 1. The message should be a complete sentence starting with an uppercase
  * letter, and ending with a period.
@@ skipping 128 matching lines @@
   COMPILER_CRASHED,
   COMPLEX_RETURNING_NSM,
   COMPLEX_THROWING_NSM,
   CONSIDER_ANALYZE_ALL,
   CONST_CALLS_NON_CONST,
   CONST_CALLS_NON_CONST_FOR_IMPLICIT,
   CONST_CONSTRUCTOR_HAS_BODY,
   CONST_CONSTRUCTOR_WITH_NONFINAL_FIELDS,
   CONST_CONSTRUCTOR_WITH_NONFINAL_FIELDS_CONSTRUCTOR,
   CONST_CONSTRUCTOR_WITH_NONFINAL_FIELDS_FIELD,
+  CONST_LOOP_VARIABLE,
   CONST_MAP_KEY_OVERRIDES_EQUALS,
   CONST_WITHOUT_INITIALIZER,
   CONSTRUCTOR_CALL_EXPECTED,
   CONSTRUCTOR_IS_NOT_CONST,
   CONSTRUCTOR_WITH_RETURN_TYPE,
   CYCLIC_CLASS_HIERARCHY,
   CYCLIC_COMPILE_TIME_CONSTANTS,
   CYCLIC_REDIRECTING_FACTORY,
   CYCLIC_TYPE_VARIABLE,
   CYCLIC_TYPEDEF,
@@ skipping 1891 matching lines @@
 }"""]),
 
       MessageKind.FINAL_WITHOUT_INITIALIZER:
         const MessageTemplate(MessageKind.FINAL_WITHOUT_INITIALIZER,
           "A final variable must be initialized.",
           howToFix: "Try adding an initializer or "
                     "removing the 'final' modifier.",
           examples: const [
               "class C { static final field; } main() => C.field;"]),
 
+      MessageKind.CONST_LOOP_VARIABLE:
+        const MessageTemplate(MessageKind.CONST_LOOP_VARIABLE,
+          "A loop variable cannot be constant.",
+          howToFix: "Try remove the 'const' modifier or "
+                    "replacing it with a 'final' modifier.",
+          examples: const ["""
+void main() {
+  for (const c in []) {}
+}"""]),
+
       MessageKind.MEMBER_USES_CLASS_NAME:
         const MessageTemplate(MessageKind.MEMBER_USES_CLASS_NAME,
           "Member variable can't have the same name as the class it is "
           "declared in.",
           howToFix: "Try renaming the variable.",
           examples: const ["""
 class A { var A; }
 main() {
   var a = new A();
   a.A = 1;
@@ skipping 1558 matching lines @@
   static String convertToString(value) {
     if (value is ErrorToken) {
       // Shouldn't happen.
       return value.assertionMessage;
     } else if (value is Token) {
       value = value.value;
     }
     return '$value';
   }
 }