Custom IndexAccessor cannot support String index type #32706
Description
Overview
Due to the current implementation of IndexAccessor support, a custom index accessor cannot support a String index type.
The reason is that our "indexing into an object by property name" feature owns the String index type.
We should therefore ensure that a custom IndexAccessor can support a String index type and make our "indexing into an object by property name" feature the fallback, best-effort scenario.