dart2js-kernel: associate more compound assignment inner nodes

pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart

 // Copyright (c) 2016, 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.
 
 import 'package:js_runtime/shared/embedded_names.dart';
 import 'package:kernel/ast.dart' as ir;
 
 import '../constants/expressions.dart';
 import '../common.dart';
 import '../common/names.dart';
@@ skipping 180 matching lines @@
     return new Selector.getter(name);
   }
 
   Selector getSetterSelector(ir.PropertySet setter) {
     ir.Name irName = setter.name;
     Name name = new Name(
         irName.name, irName.isPrivate ? getElement(irName.library) : null);
     return new Selector.setter(name);
   }
 
-  TypeMask typeOfInvocation(ir.Expression send) {
+  TypeMask typeOfInvocation(ir.MethodInvocation send) {
     ast.Node operatorNode = kernel.nodeToAstOperator[send];
     if (operatorNode != null) {
       return _resultOf(_target).typeOfOperator(operatorNode);
     }
+    if (send.name.name == '[]=') {
+      return _compiler.closedWorld.commonMasks.dynamicType;
+    }
     return _resultOf(_target).typeOfSend(getNode(send));
   }
 
   TypeMask typeOfGet(ir.PropertyGet getter) {
     return _resultOf(_target).typeOfSend(getNode(getter));
   }
 
   TypeMask typeOfSet(ir.PropertySet setter) {
     return _compiler.closedWorld.commonMasks.dynamicType;
   }
@@ skipping 614 matching lines @@
     astAdapter.reporter.internalError(
         CURRENT_ELEMENT_SPANNABLE, "Unexpected constant target: $element.");
     return null;
   }
 
   @override
   ConstantExpression visitStringLiteral(ir.StringLiteral node) {
     return new StringConstantExpression(node.value);
   }
 }