Track async causal stack traces

runtime/vm/intrinsifier_mips.cc

 // Copyright (c) 2013, 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"  // Needed here to get TARGET_ARCH_MIPS.
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/intrinsifier.h"
 
 #include "vm/assembler.h"
@@ skipping 2405 matching lines @@
   // Load TimelineStream*.
   __ lw(V0, Address(THR, Thread::dart_stream_offset()));
   // Load uintptr_t from TimelineStream*.
   __ lw(T0, Address(V0, TimelineStream::enabled_offset()));
   __ LoadObject(V0, Bool::True());
   __ LoadObject(V1, Bool::False());
   __ Ret();
   __ delay_slot()->movz(V0, V1, T0);  // V0 = (T0 == 0) ? V1 : V0.
 }
 
+
+void Intrinsifier::ClearAsyncThreadStackTrace(Assembler* assembler) {
+  __ LoadObject(V0, Object::null_object());
+  __ sw(V0, Address(THR, Thread::async_stack_trace_offset()));
+  __ Ret();
+}
+
+
+void Intrinsifier::SetAsyncThreadStackTrace(Assembler* assembler) {
+  __ lw(V0, Address(THR, Thread::async_stack_trace_offset()));
+  __ LoadObject(V0, Object::null_object());
+  __ Ret();
+}
+
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS