Mapper for C string arrays.
Collection used for caching generated native C string arrays.
Because this is a weak has map, the C string arrays will be released after every Java reference to them is gone.
Throws runtime error, because there is no way to support this direction.
Creates a C string array.
At first it lookups in the cache, if it results in a success, then it uses it as a result. Otherwise, it creates a C string array and cache it in strings2addr and returns it.