[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/parsing/parser.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 270 matching lines @@
 }
 
 
 void ALAA::VisitCountOperation(CountOperation* e) {
   Expression* l = e->expression();
   Visit(l);
   if (l->IsVariableProxy()) AnalyzeAssignment(l->AsVariableProxy()->var());
 }
 
 
+void ALAA::VisitRewritableAssignmentExpression(
+    RewritableAssignmentExpression* expr) {
+  Visit(expr->expression());
+}
+
+
 void ALAA::AnalyzeAssignment(Variable* var) {
   if (!loop_stack_.empty() && var->IsStackAllocated()) {
     loop_stack_.back()->Add(GetVariableIndex(info()->scope(), var));
   }
 }
 
 
 int ALAA::GetVariableIndex(Scope* scope, Variable* var) {
   CHECK(var->IsStackAllocated());
   if (var->is_this()) return 0;
   if (var->IsParameter()) return 1 + var->index();
   return 1 + scope->num_parameters() + var->index();
 }
 
 
 int LoopAssignmentAnalysis::GetAssignmentCountForTesting(Scope* scope,
                                                          Variable* var) {
   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