Clean up ScopedThreadStateChange to use ObjPtr

Also fixed inclusion of -inl.h files in .h files by adding
scoped_object_access-inl.h and scoped_fast_natvie_object_access-inl.h

Changed AddLocalReference / Decode to use ObjPtr.

Changed libartbenchmark to be debug to avoid linkage errors.

Bug: 31113334

Test: test-art-host

Change-Id: I4d2e160483a29d21e1e0e440585ed328b9811483
diff --git a/runtime/gc/heap_test.cc b/runtime/gc/heap_test.cc
index a3cefd9..515a6fd 100644
--- a/runtime/gc/heap_test.cc
+++ b/runtime/gc/heap_test.cc
@@ -22,7 +22,7 @@
 #include "mirror/class-inl.h"
 #include "mirror/object-inl.h"
 #include "mirror/object_array-inl.h"
-#include "scoped_thread_state_change.h"
+#include "scoped_thread_state_change-inl.h"
 
 namespace art {
 namespace gc {