[es6] implement destructuring assignment

src/crankshaft/typing.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/crankshaft/typing.h"
 
 #include "src/frames.h"
 #include "src/frames-inl.h"
 #include "src/ostreams.h"
 #include "src/parser.h"  // for CompileTimeValue; TODO(rossberg): should move
@@ skipping 419 matching lines @@
   for (int i = 0; i < values->length(); ++i) {
     Expression* value = values->at(i);
     RECURSE(Visit(value));
   }
 
   NarrowType(expr, Bounds(Type::Object(zone())));
 }
 
 
 void AstTyper::VisitAssignment(Assignment* expr) {
+  RETURN_IF_VISIT_NODE(expr->destructuring_assignment());
+
   // Collect type feedback.
   Property* prop = expr->target()->AsProperty();
   if (prop != NULL) {
     FeedbackVectorSlot slot = expr->AssignmentSlot();
     expr->set_is_uninitialized(oracle()->StoreIsUninitialized(slot));
     if (!expr->IsUninitialized()) {
       SmallMapList* receiver_types = expr->GetReceiverTypes();
       if (prop->key()->IsPropertyName()) {
         Literal* lit_key = prop->key()->AsLiteral();
         DCHECK(lit_key != NULL && lit_key->value()->IsString());
@@ skipping 340 matching lines @@
 void AstTyper::VisitImportDeclaration(ImportDeclaration* declaration) {
 }
 
 
 void AstTyper::VisitExportDeclaration(ExportDeclaration* declaration) {
 }
 
 
 }  // namespace internal
 }  // namespace v8