[es6] Correct parsing of regular expression literal flags.

src/full-codegen/x64/full-codegen-x64.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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
 #include "src/debug/debug.h"
@@ skipping 1398 matching lines @@
     }
   }
 }
 
 
 void FullCodeGenerator::VisitRegExpLiteral(RegExpLiteral* expr) {
   Comment cmnt(masm_, "[ RegExpLiteral");
   __ movp(rdi, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
   __ Move(rax, Smi::FromInt(expr->literal_index()));
   __ Move(rcx, expr->pattern());
-  __ Move(rdx, expr->flags());
+  __ Move(rdx, Smi::FromInt(expr->flags()));
   FastCloneRegExpStub stub(isolate());
   __ CallStub(&stub);
   context()->Plug(rax);
 }
 
 
 void FullCodeGenerator::EmitAccessor(ObjectLiteralProperty* property) {
   Expression* expression = (property == NULL) ? NULL : property->value();
   if (expression == NULL) {
     __ PushRoot(Heap::kNullValueRootIndex);
@@ skipping 3456 matching lines @@
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64