Uses double load/store on arm64, enables tests.

runtime/vm/disassembler_arm64.cc

 // Copyright (c) 2014, 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/disassembler.h"
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 #include "platform/assert.h"
 
@@ skipping 595 matching lines @@
         if (((instr->RdField() == R31) || (instr->RnField() == R31)) &&
             (instr->Imm12Field() == 0) && (instr->Bit(29) == 0)) {
           Format(instr, "mov'sf 'rd, 'rn");
         } else {
           Format(instr, "addi'sf's 'rd, 'rn, 'imm12s");
         }
       }
       break;
     }
     case 1: {
-      if ((instr->RdField() == R31) && (instr->SFField())) {
+      if ((instr->RdField() == R31) && (instr->SField() == 1)) {
         Format(instr, "cmpi'sf 'rn, 'imm12s");
       } else {
         Format(instr, "subi'sf's 'rd, 'rn, 'imm12s");
       }
       break;
     }
     default:
       Unknown(instr);
       break;
   }
@@ skipping 425 matching lines @@
                                   human_buffer,
                                   sizeof(human_buffer),
                                   pc);
     pc += instruction_length;
   }
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM