fix: resolve NPE in enum processing

jadx-core/src/main/java/jadx/core/dex/visitors/EnumVisitor.java

@@ -192,12 +192,13 @@ public class EnumVisitor extends AbstractVisitor {
 		if (ctrMth != null) {
 			markArgsForSkip(ctrMth);
 		}
-		if (co.getResult().getSVar().getUseList().size() <= 2) {
+		RegisterArg coResArg = co.getResult();
+		if (coResArg == null || coResArg.getSVar().getUseList().size() <= 2) {
 			InsnRemover.removeWithoutUnbind(classInitMth, staticBlock, co);
 		} else {
 			// constructor result used in other places -> replace constructor with enum field get (SGET)
 			IndexInsnNode enumGet = new IndexInsnNode(InsnType.SGET, enumField.getField().getFieldInfo(), 0);
-			enumGet.setResult(co.getResult().duplicate());
+			enumGet.setResult(coResArg.duplicate());
 			BlockUtils.replaceInsn(classInitMth, staticBlock, co, enumGet);
 		}
 	}