[es6] disable optimization in lazily parsed arrows with rest params

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/ast-literal-reindexer.h"
 #include "src/bailout-reason.h"
@@ skipping 1198 matching lines @@
           // previously. If not, parsing has been interrupted due to a stack
           // overflow, at which point the partially parsed arrow function
           // concise body happens to be a valid expression. This is a problem
           // only for arrow functions with single expression bodies, since there
           // is no end token such as "}" for normal functions.
           if (scanner()->location().end_pos == shared_info->end_position()) {
             // The pre-parser saw an arrow function here, so the full parser
             // must produce a FunctionLiteral.
             DCHECK(expression->IsFunctionLiteral());
             result = expression->AsFunctionLiteral();
+            if (scope->has_rest_parameter()) {
+              // TODO(caitp): enable optimization of functions with rest params
+              result->set_dont_optimize_reason(kRestParameter);
+            }
           } else {
             ok = false;
           }
         }
       }
     } else if (shared_info->is_default_constructor()) {
       result = DefaultConstructor(IsSubclassConstructor(shared_info->kind()),
                                   scope, shared_info->start_position(),
                                   shared_info->end_position());
     } else {
@@ skipping 4713 matching lines @@
 Expression* Parser::SpreadCallNew(Expression* function,
                                   ZoneList<v8::internal::Expression*>* args,
                                   int pos) {
   args->InsertAt(0, function, zone());
 
   return factory()->NewCallRuntime(
       ast_value_factory()->reflect_construct_string(), NULL, args, pos);
 }
 }  // namespace internal
 }  // namespace v8