Auto merge of #927 - RalfJung:getrandom, r=RalfJung
Auto merge of #927 - RalfJung:getrandom, r=RalfJung

explicitly enable getrandom/std feature

This seems to be what rand_core does, and then we need to do it as well or else the rustc feature checker complains.

rust-lang/miri,rust-lang/miri,rust-lang/miri,tsion/miri,rust-lang/miri