Remove Frame, merge shadow and quick representations.

Change-Id: I5ae03a5e52111792d2df7e83cbd89ab25777844b
diff --git a/src/runtime.cc b/src/runtime.cc
index d7bef1e..b071ef4 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -862,7 +862,7 @@
   if (self == NULL) {
     LOG(FATAL) << "attempting to detach thread that is not attached";
   }
-  if (self->GetTopOfStack().GetSP() != NULL) {
+  if (self->HasManagedStack()) {
     LOG(FATAL) << *Thread::Current() << " attempting to detach while still running code";
   }
   thread_list_->Unregister();