Optimize num::~/, num::>> and num::<< for some cases.

sdk/lib/_internal/compiler/implementation/ssa/tracer.dart

 // Copyright (c) 2013, 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 tracer;
 
 import 'dart:async' show EventSink;
 
 import 'ssa.dart';
 import '../js_backend/js_backend.dart';
@@ skipping 460 matching lines @@
   }
 
   String visitThis(HThis node) => "this";
 
   String visitThrow(HThrow node) => "Throw ${temporaryId(node.inputs[0])}";
 
   String visitThrowExpression(HThrowExpression node) {
     return "ThrowExpression ${temporaryId(node.inputs[0])}";
   }
 
+  String visitTruncatingDivide(HTruncatingDivide node) {
+    return handleInvokeBinary(node, '~/');
+  }
+
   String visitExitTry(HExitTry node) {
     return "Exit try";
   }
 
   String visitTry(HTry node) {
     List<HBasicBlock> successors = currentBlock.successors;
     String tryBlock = 'B${successors[0].id}';
     String catchBlock = 'none';
     if (node.catchBlock != null) {
       catchBlock = 'B${successors[1].id}';
@@ skipping 44 matching lines @@
   }
 
   String visitInterfaceType(HInterfaceType node) {
     return "InterfaceType: ${node.dartType}";
   }
 
   String visitDynamicType(HDynamicType node) {
     return "DynamicType";
   }
 }