Require two type arguments for map literals (issue 4522).

lib/compiler/implementation/resolver.dart

 // 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.
 
 interface TreeElements {
   Element operator[](Node node);
   Selector getSelector(Send send);
   Type getType(TypeAnnotation annotation);
 }
 
@@ skipping 1582 matching lines @@
     }
   }
 
   visitLabel(Label node) {
     // Labels are handled by their containing statements/cases.
   }
 
   visitLabeledStatement(LabeledStatement node) {
     Statement body = node.statement;
     TargetElement targetElement = getOrCreateTargetElement(body);
-    Map<String, LabelElement> labelElements = <LabelElement>{};
+    Map<String, LabelElement> labelElements = <String, LabelElement>{};
     for (Label label in node.labels) {
       String labelName = label.slowToString();
       if (labelElements.containsKey(labelName)) continue;
       LabelElement element = targetElement.addLabel(label, labelName);
       labelElements[labelName] = element;
     }
     statementScope.enterLabelScope(labelElements);
     visit(node.statement);
     statementScope.exitLabelScope();
     labelElements.forEach((String labelName, LabelElement element) {
@@ skipping 19 matching lines @@
   }
 
   visitNamedArgument(NamedArgument node) {
     visit(node.expression);
   }
 
   visitSwitchStatement(SwitchStatement node) {
     node.expression.accept(this);
 
     TargetElement breakElement = getOrCreateTargetElement(node);
-    Map<String, LabelElement> continueLabels = <LabelElement>{};
+    Map<String, LabelElement> continueLabels = <String, LabelElement>{};
     Link<Node> cases = node.cases.nodes;
     while (!cases.isEmpty()) {
       SwitchCase switchCase = cases.head;
       for (Node labelOrCase in switchCase.labelsAndCases) {
         if (labelOrCase is! Label) continue;
         Label label = labelOrCase;
         String labelName = label.slowToString();
 
         LabelElement existingElement = continueLabels[labelName];
         if (existingElement !== null) {
@@ skipping 785 matching lines @@
   TopScope(LibraryElement library) : super(null, library);
   Element lookup(SourceString name) {
     return library.find(name);
   }
 
   Element add(Element newElement) {
     throw "Cannot add an element in the top scope";
   }
   String toString() => '$element';
 }