Indexer properties are not correctly looked up from type registry
Description
Given a custom property registry AA which has A as parent. Given property x.y which is a collection of type Y. Looking up x.y will go to the property registry of X to fetch Y, but x.y[] will not.
Given a custom property registry AA which has A as parent.
Given property x.y which is a collection of type Y.
Looking up x.y will go to the property registry of X to fetch Y, but x.y[] will not.