Fix debug build breakage from r3740

src/x64/codegen-x64.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 6686 matching lines @@
   __ movl(rdx, rbx);
   __ andb(rdx, Immediate(kStringRepresentationMask));
   __ cmpb(rdx, Immediate(kConsStringTag));
   __ j(not_equal, &runtime);
   __ movq(rdx, FieldOperand(rax, ConsString::kSecondOffset));
   __ Cmp(rdx, Factory::empty_string());
   __ j(not_equal, &runtime);
   __ movq(rax, FieldOperand(rax, ConsString::kFirstOffset));
   __ movq(rbx, FieldOperand(rax, HeapObject::kMapOffset));
   __ movzxbl(rbx, FieldOperand(rbx, Map::kInstanceTypeOffset));
-  ASSERT_EQ(0, kSequentialStringTag);
+  ASSERT_EQ(0, kSeqStringTag);
   __ testb(rbx, Immediate(kStringRepresentationMask));
   __ j(not_zero, &runtime);
   __ andb(rbx, Immediate(kStringRepresentationEncodingMask));
 
   __ bind(&seq_string);
   // rax: subject string (sequential either ascii to two byte)
   // rbx: suject string type & kStringRepresentationEncodingMask
   // rcx: RegExp data (FixedArray)
   // Check that the irregexp code has been generated for an ascii string. If
   // it has, the field contains a code object otherwise it contains the hole.
@@ skipping 2489 matching lines @@
   // Call the function from C++.
   return FUNCTION_CAST<ModuloFunction>(buffer);
 }
 
 #endif
 
 
 #undef __
 
 } }  // namespace v8::internal