Fix asserts in StackFrameIterator which were effectively disabled

runtime/vm/simulator_arm64.cc

Index: runtime/vm/simulator_arm64.cc
diff --git a/runtime/vm/simulator_arm64.cc b/runtime/vm/simulator_arm64.cc
index 7df213e02746c900020f865f9984068586f4fb98..455bac6e80228a81c3d86dbb0bf4d64dce8b7cd7 100644
--- a/runtime/vm/simulator_arm64.cc
+++ b/runtime/vm/simulator_arm64.cc
@@ -303,9 +303,10 @@ void SimulatorDebugger::PrintDartFrame(uword pc,
 
 
 void SimulatorDebugger::PrintBacktrace() {
-  StackFrameIterator frames(sim_->get_register(FP), sim_->get_register(SP),
-                            sim_->get_pc(),
-                            StackFrameIterator::kDontValidateFrames);
+  StackFrameIterator frames(
+      sim_->get_register(FP), sim_->get_register(SP), sim_->get_pc(),
+      StackFrameIterator::kDontValidateFrames, Thread::Current(),
+      StackFrameIterator::kNoCrossThreadIteration);
   StackFrame* frame = frames.NextFrame();
   ASSERT(frame != NULL);
   Function& function = Function::Handle();