Make constant map literal ordered.

pkg/analyzer/lib/src/generated/constant.dart

 // Copyright (c) 2014, 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.
 
 library analyzer.src.generated.constant;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
@@ skipping 1781 matching lines @@
   }
 
   @override
   DartObjectImpl visitMapLiteral(MapLiteral node) {
     if (node.constKeyword == null) {
       _errorReporter.reportErrorForNode(
           CompileTimeErrorCode.MISSING_CONST_IN_MAP_LITERAL, node);
       return null;
     }
     bool errorOccurred = false;
-    HashMap<DartObjectImpl, DartObjectImpl> map =
-        new HashMap<DartObjectImpl, DartObjectImpl>();
+    LinkedHashMap<DartObjectImpl, DartObjectImpl> map =
+        new LinkedHashMap<DartObjectImpl, DartObjectImpl>();
     for (MapLiteralEntry entry in node.entries) {
       DartObjectImpl keyResult = entry.key.accept(this);
       DartObjectImpl valueResult = entry.value.accept(this);
       if (keyResult == null || valueResult == null) {
         errorOccurred = true;
       } else {
         map[keyResult] = valueResult;
       }
     }
     if (errorOccurred) {
@@ skipping 3654 matching lines @@
       return BoolState.from(_element == rightElement);
     } else if (rightOperand is DynamicState) {
       return BoolState.UNKNOWN_VALUE;
     }
     return BoolState.FALSE_STATE;
   }
 
   @override
   String toString() => _element == null ? "-unknown-" : _element.name;
 }