Runtime init the cleaner instance in ResourceCleaner

Inject an accessor for the ResourceCleaner.CLEANER static variable so
that the associated cleaner won't get initialized at build time.

Closes: quarkusio#31440

extensions/resteasy-classic/rest-client/runtime/src/main/java/io/quarkus/restclient/runtime/graal/ResourceCleanerReplacement.java

@@ -0,0 +1,45 @@
+package io.quarkus.restclient.runtime.graal;
+
+import java.lang.ref.Cleaner;
+
+import com.oracle.svm.core.annotate.Alias;
+import com.oracle.svm.core.annotate.InjectAccessors;
+import com.oracle.svm.core.annotate.TargetClass;
+
+/**
+ * For GraalVM native we runtime-inject the Cleaner instance via an injected
+ * accessor. This awkward pattern over say, the initialize on demand holder
+ * pattern, is necessary so that the Graal compiler doesn't inline the accessor
+ * itself.
+ */
+@TargetClass(className = "org.jboss.resteasy.spi.ResourceCleaner")
+public final class ResourceCleanerReplacement {
+
+    @Alias
+    @InjectAccessors(CleanerAccessor.class) //
+    private static Cleaner CLEANER;
+
+    static class CleanerAccessor {
+        private static volatile Cleaner INSTANCE;
+
+        static Cleaner get() {
+            Cleaner result = INSTANCE;
+            if (result == null) {
+                // lazily initialize instance
+                result = initializeOnce();
+            }
+            return result;
+        }
+
+        private static synchronized Cleaner initializeOnce() {
+            Cleaner result = INSTANCE;
+            if (result == null) {
+                // double checked locking is ok as INSTANCE is volatile
+                result = INSTANCE = Cleaner.create();
+            }
+            return result;
+        }
+
+    }
+
+}