Add unchecked downcast methods#90851

Merged

bors merged 4 commits intorust-lang:masterfrom

ibraheemdev:downcast-unchecked

Dec 4, 2021

Commits on Nov 13, 2021

Commits on Nov 20, 2021

fix doc links for `downcast_unchecked`
ibraheemdev
committed

Commits on Dec 3, 2021

fix stability annotations for `Box::downcast`
ibraheemdev
committed