Updated MallocHooks to collect stack traces when memory is allocated.

runtime/vm/malloc_hooks_unsupported.cc

 // Copyright (c) 2017, 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 "platform/globals.h"
 
-#if !defined(DART_USE_TCMALLOC) || defined(PRODUCT)
+#if !defined(DART_USE_TCMALLOC) || defined(PRODUCT) ||                         \
+    defined(TARGET_ARCH_DBC) || defined(TARGET_OS_FUCHSIA)
 
 #include "vm/malloc_hooks.h"
 
 namespace dart {
 
 void MallocHooks::InitOnce() {
   // Do nothing.
 }
 
 
 void MallocHooks::TearDown() {
   // Do nothing.
 }
 
 
+bool MallocHooks::ProfilingEnabled() {
+  return false;
+}
+
+
+bool MallocHooks::stack_trace_collection_enabled() {
+  return false;
+}
+
+
+void MallocHooks::set_stack_trace_collection_enabled(bool enabled) {
+  // Do nothing.
+}
+
+
 void MallocHooks::ResetStats() {
   // Do nothing.
 }
 
 
 bool MallocHooks::Active() {
   return false;
 }
 
 
 void MallocHooks::PrintToJSONObject(JSONObject* jsobj) {
   // Do nothing.
 }
 
 
 intptr_t MallocHooks::allocation_count() {
   return 0;
 }
 
 
 intptr_t MallocHooks::heap_allocated_memory_in_bytes() {
   return 0;
 }
 
 }  // namespace dart
 
-#endif  // defined(DART_USE_TCMALLOC) || defined(PRODUCT)
+#endif  // !defined(DART_USE_TCMALLOC) || defined(PRODUCT) ||
+        // defined(TARGET_ARCH_DBC) || defined(TARGET_OS_FUCHSIA)