Make arm32 cpu detection recognize the DragonBoard as arm64.

runtime/vm/cpu_arm.cc

Index: runtime/vm/cpu_arm.cc
diff --git a/runtime/vm/cpu_arm.cc b/runtime/vm/cpu_arm.cc
index c2b7e762d8264fd86bd38004026b0874b5e88519..ba0f9475a64d4f797c44b6a37a96da2fcf1bc3b3 100644
--- a/runtime/vm/cpu_arm.cc
+++ b/runtime/vm/cpu_arm.cc
@@ -167,7 +167,8 @@ void HostCPUFeatures::InitOnce() {
   // 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;