fix(types): fix ref macro types

fix #4499

packages/reactivity/src/computed.ts

@@ -4,8 +4,11 @@ import { isFunction, NOOP } from '@vue/shared'
 import { ReactiveFlags, toRaw } from './reactive'
 import { Dep } from './dep'
 
+declare const ComoutedRefSymbol: unique symbol
+
 export interface ComputedRef<T = any> extends WritableComputedRef<T> {
   readonly value: T
+  [ComoutedRefSymbol]: true
 }
 
 export interface WritableComputedRef<T> extends Ref<T> {

packages/reactivity/src/ref.ts

@@ -251,7 +251,8 @@ export interface RefUnwrapBailTypes {}
 export type ShallowUnwrapRef<T> = {
   [K in keyof T]: T[K] extends Ref<infer V>
     ? V
-    : T[K] extends Ref<infer V> | undefined // if `V` is `unknown` that means it does not extend `Ref` and is undefined
+    : // if `V` is `unknown` that means it does not extend `Ref` and is undefined
+    T[K] extends Ref<infer V> | undefined
     ? unknown extends V
       ? undefined
       : V | undefined