Set TARGET_OS_* from GN, falling back to HOST_OS_*.

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 64 matching lines @@
 #else
 DEFINE_FLAG(bool, use_vfp, true, "Use vfp instructions if supported");
 DEFINE_FLAG(bool, use_neon, true, "Use neon instructions if supported");
 DEFINE_FLAG(bool,
             use_integer_division,
             true,
             "Use integer division instruction if supported");
 #endif
 
 #if defined(USING_SIMULATOR)
-#if defined(TARGET_ARCH_ARM_5TE)
-DEFINE_FLAG(bool, sim_use_hardfp, false, "Use the softfp ABI.");
+#if defined(TARGET_ARCH_ARM_5TE) || defined(TARGET_OS_ANDROID)
+DEFINE_FLAG(bool, sim_use_hardfp, false, "Use the hardfp ABI.");
 #else
-DEFINE_FLAG(bool, sim_use_hardfp, true, "Use the softfp ABI.");
+DEFINE_FLAG(bool, sim_use_hardfp, true, "Use the hardfp ABI.");
 #endif
 #endif
 
 void CPU::FlushICache(uword start, uword size) {
 #if HOST_OS_IOS
   // Precompilation never patches code so there should be no I cache flushes.
   UNREACHABLE();
 #endif
 
 #if !defined(USING_SIMULATOR) && !HOST_OS_IOS
@@ skipping 184 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