Prune portals (#4667)

Author: JoviDeCroock

compat/src/portals.js

@@ -46,14 +46,9 @@ function Portal(props) {
 			parentNode: container,
 			childNodes: [],
 			_children: { _mask: root._mask },
-			contains: () => true,
 			insertBefore(child, before) {
 				this.childNodes.push(child);
 				_this._container.insertBefore(child, before);
-			},
-			removeChild(child) {
-				this.childNodes.splice(this.childNodes.indexOf(child) >>> 1, 1);
-				_this._container.removeChild(child);
 			}
 		};
 	}