Fails on nightly due to a recent stabilisation

[tirkarthi]

Build fails due on nightly due to a recent stabilization. It seems to break a lot of modules in the ecosystem.

Discussion in the PR : rust-lang/rust#49305
RFC : rust-lang/rfcs#1542
Tracking issue : rust-lang/rust#33417

Probably caused due to stdweb

Upstream issue : koute/stdweb#175

[pitdicker]

Thank you for reporting, we reported the issue to stdweb 😄.
But there is nothing here that is an issue with rand, only with rustc and stdweb.