Reimplement associative arrays on runtime

[dlangBugzillaToGithub]

Marcelo Silva Nascimento Mancini reported this on 2023-01-05T19:38:14Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=23602

Description

Current D Runtime Associative Array is pretty buggy. 
After talking with some, people, its implementation was done even before D having templates, so, it should not be too hard to do it better than how it is now[1]. 
Right no no one wanted to rework on it, but everyone which tried doing a custom druntime basically dropped support for associative arrays given how confusing is to implement them.
 I'm working on them for Adam's minimal runtime and I just saw that implementing them would basically be as complex as implementing everything that has been done so far for this minimal wasm runtime.

There is some proposals such as mapping Associative Array to a library type rather than doing bunch of hooks, which seems to be a better solution for the long run.

[1]: Steve has done a new associative array implementation that maps to the current one, it has roughly 1/3 LoC the current one has and it is a lot easier to understand: https://github.com/schveiguy/newaa/blob/master/source/schlib/newaa.d

[schveiguy]

I think full reimplementation of the AA type in a library is going to be tough, as there are magic pieces in the compiler for inserting and using data, or implicit casting.

But we can remove usage of TypeInfo, which would simplify the implementation and expand the portability to other platforms

FYI, this was your issue @MrcSnm