Squeeze the layout of expression nodes a bit.

src/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/v8.h"
 
 #include "src/api.h"
 #include "src/ast.h"
 #include "src/bailout-reason.h"
 #include "src/base/platform/platform.h"
@@ skipping 3363 matching lines @@
 
 bool CheckAndDeclareArrowParameter(ParserTraits* traits, Expression* expression,
                                    Scope* scope, int* num_params,
                                    Scanner::Location* dupe_loc) {
   // Case for empty parameter lists:
   //   () => ...
   if (expression == NULL) return true;
 
   // Too many parentheses around expression:
   //   (( ... )) => ...
-  if (expression->parenthesization_level() > 1) return false;
+  if (expression->is_multi_parenthesized()) return false;
 
   // Case for a single parameter:
   //   (foo) => ...
   //   foo => ...
   if (expression->IsVariableProxy()) {
     if (expression->AsVariableProxy()->is_this()) return false;
 
     const AstRawString* raw_name = expression->AsVariableProxy()->raw_name();
     if (traits->IsEvalOrArguments(raw_name) ||
         traits->IsFutureStrictReserved(raw_name))
@@ skipping 1573 matching lines @@
 
   // We cannot internalize on a background thread; a foreground task will take
   // care of calling Parser::Internalize just before compilation.
 
   if (compile_options() == ScriptCompiler::kProduceParserCache) {
     if (result != NULL) *info_->cached_data() = recorder.GetScriptData();
     log_ = NULL;
   }
 }
 } }  // namespace v8::internal