Make arm32 cpu detection recognize the DragonBoard as arm64.

runtime/vm/cpu_arm.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"
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/cpu.h"
 #include "vm/cpu_arm.h"
 
@@ skipping 149 matching lines @@
 }
 #else  // TARGET_OS_IOS
 void HostCPUFeatures::InitOnce() {
   bool is_arm64 = false;
   CpuInfo::InitOnce();
   hardware_ = CpuInfo::GetCpuModel();
 
   // Check for ARMv5TE, ARMv6, ARMv7, or aarch64.
   // It can be in either the Processor or Model information fields.
   if (CpuInfo::FieldContains(kCpuInfoProcessor, "aarch64") ||
-      CpuInfo::FieldContains(kCpuInfoModel, "aarch64")) {
+      CpuInfo::FieldContains(kCpuInfoModel, "aarch64") ||
+      CpuInfo::FieldContains(kCpuInfoArchitecture, "8")) {

[zra, 2016/11/14 23:57:08]

Also check if this is AArch64 as reported by Android sometimes.

[rmacnak, 2016/11/15 00:46:27]

Done.

     // pretend that this arm64 cpu is really an ARMv7
     arm_version_ = ARMv7;
     is_arm64 = true;
   } else if (CpuInfo::FieldContains(kCpuInfoProcessor, "ARM926EJ-S") ||
              CpuInfo::FieldContains(kCpuInfoModel, "ARM926EJ-S")) {
     // Lego Mindstorm EV3.
     arm_version_ = ARMv5TE;
     // On ARMv5, the PC read offset in an STR or STM instruction is either 8 or
     // 12 bytes depending on the implementation. On the Mindstorm EV3 it is 12
     // bytes.
@@ skipping 99 matching lines @@
   ASSERT(hardware_ != NULL);
   free(const_cast<char*>(hardware_));
   hardware_ = NULL;
   CpuInfo::Cleanup();
 }
 #endif  // !defined(USING_SIMULATOR)
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM