fix(runtime-core): `in` operator returning `false` for built-in instance properties in `exposeProxy` (fix #6137)#6138

yyx990803 merged 4 commits intovuejs:mainvuejs/core:mainfrom

DrJume:fix/expose-proxy-in-operatorDrJume/vuejs-core:fix/expose-proxy-in-operatorCopy head branch name to clipboard