Comment 15 for bug 1863162

(In reply to Pádraig Brady from comment #11)
> This has been _very_ well tested at facebook
> Note the additional fix in comment #9
> It would be great to merge this. thanks!

sorry i didnt have time to work on this in this release cycle, i'll try to look at it in the next one if others don't beat me to it (the comments can be improved, dtv_slots should be fixed so it has consistent meaning and one should reason about the consequences of removing the asserts, they might catch valid corruption that is still present via dlclose races that are not fixed).