diff a/src/hotspot/share/opto/loopnode.hpp b/src/hotspot/share/opto/loopnode.hpp
--- a/src/hotspot/share/opto/loopnode.hpp
+++ b/src/hotspot/share/opto/loopnode.hpp
@@ -873,11 +873,10 @@
 // Computes the mapping from Nodes to IdealLoopTrees. Organizes IdealLoopTrees
 // into a loop tree. Drives the loop-based transformations on the ideal graph.
 class PhaseIdealLoop : public PhaseTransform {
   friend class IdealLoopTree;
   friend class SuperWord;
-  friend class ShenandoahBarrierC2Support;
   friend class AutoNodeBudget;
 
   Arena _arena; // For data whose lifetime is a single pass of loop optimizations
 
   // Map loop membership for CFG nodes, and ctrl for non-CFG nodes.