[es6] enable destructuring rest parameters

src/parsing/parser.cc

 // Copyright 2012 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/parsing/parser.h"
 
 #include "src/api.h"
 #include "src/ast/ast.h"
 #include "src/ast/ast-expression-visitor.h"
 #include "src/ast/ast-literal-reindexer.h"
@@ skipping 4460 matching lines @@
 
 
 Block* Parser::BuildParameterInitializationBlock(
     const ParserFormalParameters& parameters, bool* ok) {
   DCHECK(!parameters.is_simple);
   DCHECK(scope_->is_function_scope());
   Block* init_block =
       factory()->NewBlock(NULL, 1, true, RelocInfo::kNoPosition);
   for (int i = 0; i < parameters.params.length(); ++i) {
     auto parameter = parameters.params[i];
-    if (parameter.is_rest) break;
+    if (parameter.is_rest && parameter.pattern->IsVariableProxy()) break;
     DeclarationDescriptor descriptor;
     descriptor.declaration_kind = DeclarationDescriptor::PARAMETER;
     descriptor.parser = this;
     descriptor.scope = scope_;
     descriptor.hoist_scope = nullptr;
     descriptor.mode = LET;
     descriptor.needs_init = true;
     descriptor.declaration_pos = parameter.pattern->position();
     // The position that will be used by the AssignmentExpression
     // which copies from the temp parameter to the pattern.
@@ skipping 960 matching lines @@
     auto class_literal = value->AsClassLiteral();
     if (class_literal->raw_name() == nullptr) {
       class_literal->set_raw_name(name);
     }
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8