[es6] implement destructuring assignment

src/compiler/ast-loop-assignment-analyzer.cc

 // Copyright 2014 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/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler.h"
 #include "src/parser.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 256 matching lines @@
   Enter(loop);
   Visit(loop->assign_each());
   Visit(loop->each());
   Visit(loop->subject());
   Visit(loop->body());
   Exit(loop);
 }
 
 
 void ALAA::VisitAssignment(Assignment* stmt) {
+  RETURN_IF_VISIT_NODE(stmt->destructuring_assignment());
+
   Expression* l = stmt->target();
   Visit(l);
   Visit(stmt->value());
   if (l->IsVariableProxy()) AnalyzeAssignment(l->AsVariableProxy()->var());
 }
 
 
 void ALAA::VisitCountOperation(CountOperation* e) {
   Expression* l = e->expression();
   Visit(l);
@@ skipping 21 matching lines @@
   int count = 0;
   int var_index = AstLoopAssignmentAnalyzer::GetVariableIndex(scope, var);
   for (size_t i = 0; i < list_.size(); i++) {
     if (list_[i].second->Contains(var_index)) count++;
   }
   return count;
 }
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8