Remove support for >>> and >>>= operators in dartc

compiler/java/com/google/dart/compiler/backend/js/Normalizer.java

Index: compiler/java/com/google/dart/compiler/backend/js/Normalizer.java
diff --git a/compiler/java/com/google/dart/compiler/backend/js/Normalizer.java b/compiler/java/com/google/dart/compiler/backend/js/Normalizer.java
index 582de60267ae3d509fb01d2dc0047dd6055ca174..18947a9d5b8cc733ac2e3a07f31225e403fa512f 100644
--- a/compiler/java/com/google/dart/compiler/backend/js/Normalizer.java
+++ b/compiler/java/com/google/dart/compiler/backend/js/Normalizer.java
@@ -1,16 +1,9 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// 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.
 
 package com.google.dart.compiler.backend.js;
 
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
-
 import com.google.common.collect.Lists;
 import com.google.dart.compiler.InternalCompilerException;
 import com.google.dart.compiler.ast.DartArrayAccess;
@@ -73,6 +66,13 @@ import com.google.dart.compiler.resolver.VariableElement;
 import com.google.dart.compiler.type.InterfaceType;
 import com.google.dart.compiler.type.Types;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
 /**
  * Normalization phase of Dart compiler. Rewrites the AST to simplify later
  * phases.
@@ -1004,7 +1004,6 @@ public class Normalizer {
         case ASSIGN_BIT_AND: return Token.BIT_AND;
         case ASSIGN_SHL: return Token.SHL;
         case ASSIGN_SAR: return Token.SAR;
-        case ASSIGN_SHR: return Token.SHR;
         case ASSIGN_ADD: return Token.ADD;
         case ASSIGN_SUB: return Token.SUB;
         case ASSIGN_MUL: return Token.MUL;