Begins work on ARM64, first assembler test.

runtime/vm/disassembler_test.cc

 // Copyright (c) 2011, 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.
 
+// TODO(zra): Remove when tests are ready to enable.
+#include "platform/globals.h"
+#if !defined(TARGET_ARCH_ARM64)
+
 #include "vm/assembler.h"
 #include "vm/disassembler.h"
 #include "vm/unit_test.h"
 #include "vm/virtual_memory.h"
 
 namespace dart {
 
 TEST_CASE(Disassembler) {
   Assembler assembler;
   // The used instructions work on all platforms.
   Register reg = static_cast<Register>(0);
   assembler.PopRegister(reg);
   assembler.Stop("testing disassembler");
 
   // Only verify that the disassembler does not crash.
   AssemblerTest test("Disassembler", &assembler);
   test.Assemble();
   Disassembler::Disassemble(test.entry(), test.entry() + assembler.CodeSize());
 }
 
 }  // namespace dart
+
+#endif  // !defined(TARGET_ARCH_ARM64)