fix(runtime-core): Avoid mutating original options object in createApp (#4840)

fix #4398

packages/runtime-core/src/apiCreateApp.ts

@@ -179,6 +179,11 @@ export function createAppAPI<HostElement>(
   hydrate?: RootHydrateFunction
 ): CreateAppFunction<HostElement> {
   return function createApp(rootComponent, rootProps = null) {
+
+    if (!isFunction(rootComponent)) {
+      rootComponent = { ...rootComponent }
+    }
+
     if (rootProps != null && !isObject(rootProps)) {
       __DEV__ && warn(`root props passed to app.mount() must be an object.`)
       rootProps = null