Remove some unused functions from Object.prototype

sdk/lib/_internal/compiler/implementation/js_backend/native_emitter.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.
 
 part of js_backend;
 
 class NativeEmitter {
 
   CodeEmitterTask emitter;
   CodeBuffer nativeBuffer;
@@ skipping 478 matching lines @@
         String name = backend.namer.operatorIs(element);
         addProperty(name,
             js.fun([], js.return_(js('false'))));
         // Add a function for the (trivial) substitution.
         addProperty(backend.namer.substitutionName(element),
                     js.fun([], js.return_(js('null'))));
       }
     }
     emitIsChecks();
 
-    jsAst.Expression makeCallOnThis(String functionName) {
-      // Because we know the function is intercepted, we need an extra
-      // parameter.
-      return js.fun(['_'], js.return_(js('$functionName(this)')));
-    }
-
     if (!nativeClasses.isEmpty) {
       emitDynamicDispatchMetadata();
 
-      // In order to have the toString method on every native class,
-      // we must patch the JS Object prototype with a helper method.
-      String toStringName = backend.namer.publicInstanceMethodNameByArity(
-          const SourceString('toString'), 0);
-      addProperty(toStringName, makeCallOnThis(toStringHelperName));
-
-      // Same as above, but for hashCode.
-      String hashCodeName =
-          backend.namer.publicGetterName(const SourceString('hashCode'));
-      addProperty(hashCodeName, makeCallOnThis(hashCodeHelperName));
-
-      // Same as above, but for operator==.
-      String equalsName = backend.namer.publicInstanceMethodNameByArity(
-          const SourceString('=='), 1);
-      // Because we know the function is intercepted, we need an extra
-      // parameter.
-      addProperty(equalsName, js.fun(['_', 'a'],
-          js.return_(js('this === a'))));
-
       // If the native emitter has been asked to take care of the
       // noSuchMethod handlers, we do that now.
       if (handleNoSuchMethod) {
         emitter.emitNoSuchMethodHandlers(addProperty);
       }
     }
 
     // If we have any properties to add to Object.prototype, we run
     // through them and add them using defineProperty.
     if (!objectProperties.isEmpty) {
@@ skipping 12 matching lines @@
       if (emitter.compiler.enableMinification) targetBuffer.add(';');
       targetBuffer.add(jsAst.prettyPrint(
           new jsAst.ExpressionStatement(init), compiler));
       targetBuffer.add('\n');
     }
 
     targetBuffer.add(nativeBuffer);
     targetBuffer.add('\n');
   }
 }