fix(runtime-core): properties in methods should be writable and enumerable in DEV (#3301)

fix #3300

packages/runtime-core/src/componentOptions.ts

@@ -610,7 +610,8 @@ export function applyOptions(
           Object.defineProperty(ctx, key, {
             value: methodHandler.bind(publicThis),
             configurable: true,
-            enumerable: false
+            enumerable: true,
+            writable: true
           })
         } else {
           ctx[key] = methodHandler.bind(publicThis)