Improve ConstantFieldFeature compatibility

This commit makes ConstantFieldFeature
compatible with GraalVM 22.2 while retaining
GraalVM 22.1 compatibility.

See spring-projectsgh-28624

spring-core/graalvm/src/main/java/org/springframework/aot/graalvm/ConstantFieldFeature.java

@@ -41,9 +41,9 @@ private void duringSetup(DuringSetupAccessImpl access) {
 		DebugContext debug = access.getDebugContext();
 		try (DebugContext.Scope scope = debug.scope("ConstantFieldFeature.duringSetup")) {
 			debug.log("Installing constant field substitution processor : " + scope);
-			ClassLoader applicationClassLoader = access.getApplicationClassLoader();
+			ClassLoader classLoader = ConstantFieldFeature.class.getClassLoader();
 			ConstantFieldSubstitutionProcessor substitutionProcessor =
-					new ConstantFieldSubstitutionProcessor(debug, applicationClassLoader);
+					new ConstantFieldSubstitutionProcessor(debug, classLoader);
 			access.registerSubstitutionProcessor(substitutionProcessor);
 		}
 	}

spring-core/graalvm/src/main/java/org/springframework/aot/graalvm/ConstantReadableJavaField.java

@@ -18,6 +18,7 @@
 
 import java.lang.annotation.Annotation;
 
+import com.oracle.graal.pointsto.infrastructure.WrappedElement;
 import com.oracle.svm.core.meta.ReadableJavaField;
 import jdk.vm.ci.meta.JavaConstant;
 import jdk.vm.ci.meta.JavaType;
@@ -31,7 +32,7 @@
  * @author Phillip Webb
  * @since 6.0
  */
-class ConstantReadableJavaField implements ReadableJavaField {
+class ConstantReadableJavaField implements ReadableJavaField, WrappedElement {
 
 	private final ResolvedJavaField original;
 
@@ -109,4 +110,8 @@ public boolean injectFinalForRuntimeCompilation() {
 		return true;
 	}
 
+	@Override
+	public Object getWrapped() {
+		return this.original;
+	}
 }