RFR: Remove leftover from oopsHierarchy.hpp

[Roman Kennke]

We used to need an include to do our thing in oopsHierarchy.hpp, but now
we have a nice abstraction for this, so let's remove this leftover?

Testing: still builds fastdebug

diff --git a/src/hotspot/share/oops/oopsHierarchy.hpp
b/src/hotspot/share/oops/oopsHierarchy.hpp
--- a/src/hotspot/share/oops/oopsHierarchy.hpp
+++ b/src/hotspot/share/oops/oopsHierarchy.hpp
@@ -28,9 +28,6 @@
 #include "metaprogramming/integralConstant.hpp"
 #include "metaprogramming/primitiveConversions.hpp"
 #include "runtime/globals.hpp"
-#if INCLUDE_SHENANDOAHGC
-#include "gc/shenandoah/shenandoah_globals.hpp"
-#endif
 #include "utilities/globalDefinitions.hpp"

 // OBJECT hierarchy