dart2js cps: More rewritings for compound assignments.

pkg/compiler/lib/src/js_backend/codegen/codegen.dart

 // Copyright (c) 2014, 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 code_generator;
 
 import 'glue.dart';
 
 import '../../closure.dart' show
     ClosureClassElement;
@@ skipping 915 matching lines @@
         new StaticUse.staticGet(node.element.declaration));
     return glue.staticFieldAccess(node.element);
   }
 
   @override
   js.Expression visitSetStatic(tree_ir.SetStatic node) {
     assert(node.element is FieldElement);
     registry.registerStaticUse(
         new StaticUse.staticSet(node.element.declaration));
     js.Expression field = glue.staticFieldAccess(node.element);
-    js.Expression value = visitExpression(node.value);
-    return new js.Assignment(field, value);
+    return makeAssignment(field, node.value, compound: node.compound);
   }
 
   @override
   js.Expression visitGetLength(tree_ir.GetLength node) {
     return new js.PropertyAccess.field(visitExpression(node.object), 'length');
   }
 
   @override
   js.Expression visitGetIndex(tree_ir.GetIndex node) {
     return new js.PropertyAccess(
@@ skipping 289 matching lines @@
   void registerDefaultParameterValues(ExecutableElement element) {
     if (element is! FunctionElement) return;
     FunctionElement function = element;
     if (function.isStatic) return; // Defaults are inlined at call sites.
     function.functionSignature.forEachOptionalParameter((param) {
       ConstantValue constant = glue.getDefaultParameterValue(param);
       registry.registerCompileTimeConstant(constant);
     });
   }
 }