implements virtual threads to fix the remaining allocator bugs for good

[Araq]

No description provided.

[Araq]

Ping @SirOlaf ; this was my solution

[arnetheduck]

• what about foreign threads / those not created by createThread?
• how do you create a leak-free program, ie how can you fully deinit the runtime (for example if it's running like a plugin in an .so that gets unloaded and reloaded?

[Araq]

@arnetheduck the API already exists:

  proc setupForeignThreadGc*() {.gcsafe.}
  proc tearDownForeignThreadGc*() {.gcsafe.}

[SirOlaf]

I am realizing that the allocator is near-impossible to benchmark properly and every tiny layout change will cause a regression somewhere while another random benchmark suddenly performs better.
If virtual threads can be made to work safely they are going to be superior in that sense, but foreign threads will run into very similar issues to the ones I have been dealing with.