[es6] Correct parsing of regular expression literal flags.

src/interpreter/bytecode-generator.cc

 // Copyright 2015 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/interpreter/bytecode-generator.h"
 
 #include "src/compiler.h"
 #include "src/interpreter/control-flow-builders.h"
 #include "src/objects.h"
 #include "src/parser.h"
@@ skipping 1024 matching lines @@
       builder()->LoadLiteral(value);
     }
     execution_result()->SetResultInAccumulator();
   }
 }
 
 
 void BytecodeGenerator::VisitRegExpLiteral(RegExpLiteral* expr) {
   // Materialize a regular expression literal.
   TemporaryRegisterScope temporary_register_scope(builder());
-  Register flags = temporary_register_scope.NewRegister();
   builder()
-      ->LoadLiteral(expr->flags())
-      .StoreAccumulatorInRegister(flags)
-      .LoadLiteral(expr->pattern())
-      .CreateRegExpLiteral(expr->literal_index(), flags);
+      ->LoadLiteral(expr->pattern())
+      .CreateRegExpLiteral(expr->literal_index(), expr->flags());
   execution_result()->SetResultInAccumulator();
 }
 
 
 void BytecodeGenerator::VisitObjectLiteral(ObjectLiteral* expr) {
   // Deep-copy the literal boilerplate.
   builder()
       ->LoadLiteral(expr->constant_properties())
       .CreateObjectLiteral(expr->literal_index(), expr->ComputeFlags(true));
 
@@ skipping 1169 matching lines @@
 }
 
 
 int BytecodeGenerator::feedback_index(FeedbackVectorSlot slot) const {
   return info()->feedback_vector()->GetIndex(slot);
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8