Make arm32 cpu detection recognize the DragonBoard as arm64.

runtime/vm/cpuinfo_fuchsia.cc

 // Copyright (c) 2016, 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"
 #if defined(TARGET_OS_FUCHSIA)
 
 #include "vm/cpuinfo.h"
 
 #include "platform/assert.h"
 #include "vm/cpuid.h"
 
 namespace dart {
 
 CpuInfoMethod CpuInfo::method_ = kCpuInfoDefault;
 const char* CpuInfo::fields_[kCpuInfoMax] = {0};
 
 void CpuInfo::InitOnce() {
 // TODO(zra): Add support for HOST_ARCH_ARM64
 #if defined(HOST_ARCH_IA32) || defined(HOST_ARCH_X64)
   method_ = kCpuInfoCpuId;
 
   // Initialize the CpuId information.
   CpuId::InitOnce();
 
   fields_[kCpuInfoProcessor] = "Processor";
   fields_[kCpuInfoModel] = "Hardware";
   fields_[kCpuInfoHardware] = "Hardware";
   fields_[kCpuInfoFeatures] = "Features";
+  fields_[kCpuInfoArchitecture] = "CPU architecture";
 #endif
 }
 
 
 void CpuInfo::Cleanup() {
   if (method_ == kCpuInfoCpuId) {
     CpuId::Cleanup();
   }
 }
 
@@ skipping 23 matching lines @@
            (strcmp(field, fields_[kCpuInfoHardware]) == 0) ||
            (strcmp(field, fields_[kCpuInfoFeatures]) == 0);
   } else {
     return false;
   }
 }
 
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_FUCHSIA)