Disable concurrent marking/sweeping, and background compilation on ARMv5TE

runtime/platform/globals.h

 // 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.
 
 #ifndef RUNTIME_PLATFORM_GLOBALS_H_
 #define RUNTIME_PLATFORM_GLOBALS_H_
 
 // __STDC_FORMAT_MACROS has to be defined before including <inttypes.h> to
 // enable platform independent printf format specifiers.
 #ifndef __STDC_FORMAT_MACROS
@@ skipping 341 matching lines @@
 #define USING_SIMULATOR 1
 #endif
 
 #elif defined(TARGET_ARCH_DBC)
 #define USING_SIMULATOR 1
 
 #else
 #error Unknown architecture.
 #endif
 
+// Disable background threads by default on armv5te. The relevant
+// implementations are uniprocessors.
+#if !defined(TARGET_ARCH_ARM_5TE)
+#define ARCH_IS_MULTI_CORE 1
+#endif
 
 // Short form printf format specifiers
 #define Pd PRIdPTR
 #define Pu PRIuPTR
 #define Px PRIxPTR
 #define Pd64 PRId64
 #define Pu64 PRIu64
 #define Px64 PRIx64
 
 // Zero-padded pointer
@@ skipping 300 matching lines @@
 // tag in the ICData and check it when recreating the flow graph in
 // optimizing compiler. Enable it for other modes (product, release) if needed
 // for debugging.
 #if defined(DEBUG)
 #define TAG_IC_DATA
 #endif
 
 }  // namespace dart
 
 #endif  // RUNTIME_PLATFORM_GLOBALS_H_