--- old/src/hotspot/share/runtime/vframe.hpp	2020-07-21 14:10:21.854515876 +0200
+++ new/src/hotspot/share/runtime/vframe.hpp	2020-07-21 14:10:21.738514143 +0200
@@ -35,6 +35,8 @@
 #include "runtime/stackValueCollection.hpp"
 #include "utilities/growableArray.hpp"
 
+class MonitorInfo;
+
 // vframes are virtual stack frames representing source level activations.
 // A single frame may hold several source level activations in the case of
 // optimized code. The debugging stored with the optimized code enables
@@ -236,46 +238,6 @@
   friend class vframe;
 };
 
-
-// A MonitorInfo is a ResourceObject that describes a the pair:
-// 1) the owner of the monitor
-// 2) the monitor lock
-class MonitorInfo : public ResourceObj {
- private:
-  Handle     _owner; // the object owning the monitor
-  BasicLock* _lock;
-  Handle     _owner_klass; // klass (mirror) if owner was scalar replaced
-  bool       _eliminated;
-  bool       _owner_is_scalar_replaced;
- public:
-  // Constructor
-  MonitorInfo(oop owner, BasicLock* lock, bool eliminated, bool owner_is_scalar_replaced, TRAPS) {
-    if (!owner_is_scalar_replaced) {
-      _owner = Handle(THREAD, owner);
-      _owner_klass = Handle();
-    } else {
-      assert(eliminated, "monitor should be eliminated for scalar replaced object");
-      _owner = Handle();
-      _owner_klass = Handle(THREAD, owner);
-    }
-    _lock  = lock;
-    _eliminated = eliminated;
-    _owner_is_scalar_replaced = owner_is_scalar_replaced;
-  }
-  // Accessors
-  oop        owner() const {
-    assert(!_owner_is_scalar_replaced, "should not be called for scalar replaced object");
-    return _owner();
-  }
-  oop   owner_klass() const {
-    assert(_owner_is_scalar_replaced, "should not be called for not scalar replaced object");
-    return _owner_klass();
-  }
-  BasicLock* lock()  const { return _lock;  }
-  bool eliminated()  const { return _eliminated; }
-  bool owner_is_scalar_replaced()  const { return _owner_is_scalar_replaced; }
-};
-
 class vframeStreamCommon : StackObj {
  protected:
   // common