Fix a typo in super ==.

runtime/vm/flow_graph_compiler_x64.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "lib/error.h"
@@ skipping 1138 matching lines @@
   const Immediate raw_null =
       Immediate(reinterpret_cast<intptr_t>(Object::null()));
   Label check_identity, fall_through;
   __ cmpq(Address(RSP, 0 * kWordSize), raw_null);
   __ j(EQUAL, &check_identity, Assembler::kNearJump);
   __ cmpq(Address(RSP, 1 * kWordSize), raw_null);
   __ j(NOT_EQUAL, &fall_through, Assembler::kNearJump);
 
   __ Bind(&check_identity);
   __ popq(result);
-  __ cmpq(result, Address(RSP, 1 * kWordSize));
+  __ cmpq(result, Address(RSP, 0 * kWordSize));
   Label is_false;
   __ j(NOT_EQUAL, &is_false, Assembler::kNearJump);
   __ LoadObject(result, bool_true());
   __ Drop(1);
   __ jmp(skip_call);
   __ Bind(&is_false);
   __ LoadObject(result, bool_false());
   __ Drop(1);
   __ jmp(skip_call);
   __ Bind(&fall_through);
@@ skipping 216 matching lines @@
 void ParallelMoveResolver::Exchange(const Address& mem1, const Address& mem2) {
   __ Exchange(mem1, mem2);
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64