Type check binary expressions

lib/src/dart_sdk.dart

 // Copyright (c) 2015, 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.
 
 /// Common logic needed to provide a Dart SDK to the analyzer's resolver. This
 /// includes logic to determine where the sdk is located in the filesystem, and
 /// definitions to provide mock sdks.
 library dev_compiler.src.dart_sdk;
 
 import 'package:analyzer/src/generated/engine.dart';
@@ skipping 95 matching lines @@
   //   _initializeFrom in resolver.dart).
   'dart:core': '''
         library dart.core;
 
         void print(Object o) {}
 
         class Object {
           int get hashCode {}
           Type get runtimeType {}
           String toString(){}
+          bool ==(other){}
         }
         class Function {}
         class StackTrace {}
         class Symbol {}
         class Type {}
 
-        class String {}
+        class String {
+          String operator +(String other) {}
+        }
         class bool {}
         class num {
           num operator +(num other) {}
         }
         class int extends num {
+          bool operator<(num other) {}
           int operator-() {}
         }
         class double extends num {}
         class DateTime {}
         class Null {}
 
         class Deprecated {
           final String expires;
           const Deprecated(this.expires);
         }
@@ skipping 16 matching lines @@
         class Future<T> {
           Future then(callback) {}
         }
         class Stream<T> {}
   ''',
   'dart:html': '''
         library dart.html;
         class HtmlElement {}
         ''',
 };