Replace enum with static final class.

Author: Michael Haas

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/nodes/InvokeJavaMethodNode.java

@@ -64,17 +64,16 @@ public class InvokeJavaMethodNode extends DeoptimizingFixedWithNextNode implemen
      * {@link InvokeJavaMethodNode} creation. See
      * {@code HotSpotTruffleSafepointLoweringSnippet#pollSnippet} for usage details.
      */
-    public enum MethodWrapper {
-        SUBSTITUTABILITY_CHECK,
-        TRUFFLE_SAFEPOINT;
-
+    public static final class MethodWrapper {
         ResolvedJavaMethod targetMethod;
 
         public void setTargetMethod(ResolvedJavaMethod targetMethod) {
             this.targetMethod = targetMethod;
         }
     }
 
+    public static final MethodWrapper TRUFFLE_SAFEPOINT = new MethodWrapper();
+
     @Input protected NodeInputList<ValueNode> arguments;
 
     private int bci;
@@ -202,7 +201,7 @@ public Invoke replaceWithInvoke() {
     public InvokeNode createInvoke(StructuredGraph graph) {
         MethodCallTargetNode callTarget = graph.add(new MethodCallTargetNode(getInvokeKind(), getTargetMethod(), toArgumentArray(), getReturnStamp(), null));
         InvokeNode in = new InvokeNode(callTarget, bci(), MemoryKill.NO_LOCATION);
-        // this node has no side-effect, propagate it to the invoke node
+        // this node has no side effect, propagate it to the invoke node
         in.setSideEffect(false);
         InvokeNode invoke = graph.add(in);
         invoke.setStateDuring(stateBefore());

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/truffle/hotspot/HotSpotTruffleSafepointLoweringSnippet.java

@@ -73,7 +73,7 @@ private static void pollSnippet(Object node, @ConstantParameter int pendingHands
         Word thread = CurrentJavaThreadNode.get();
         if (BranchProbabilityNode.probability(BranchProbabilityNode.VERY_SLOW_PATH_PROBABILITY,
                         thread.readInt(pendingHandshakeOffset, PENDING_HANDSHAKE_LOCATION) != 0)) {
-            InvokeJavaMethodNode.invoke(InvokeJavaMethodNode.MethodWrapper.TRUFFLE_SAFEPOINT, node);
+            InvokeJavaMethodNode.invoke(InvokeJavaMethodNode.TRUFFLE_SAFEPOINT, node);
         }
     }
 
@@ -152,7 +152,7 @@ public void initialize(HotSpotProviders providers,
             if (config.jvmciReserved0Offset != -1) {
                 this.templates = new Templates(options, providers, config.jvmciReserved0Offset);
                 this.deferredInit = () -> {
-                    InvokeJavaMethodNode.MethodWrapper.TRUFFLE_SAFEPOINT.setTargetMethod(types.HotSpotThreadLocalHandshake_doHandshake);
+                    InvokeJavaMethodNode.TRUFFLE_SAFEPOINT.setTargetMethod(types.HotSpotThreadLocalHandshake_doHandshake);
                 };
             }
         }