Beta next#45948

Merged

bors merged 3 commits intorust-lang:betafrom

Mark-Simulacrum:beta-next

Nov 13, 2017

Commits on Nov 12, 2017

Update cargo to include a few bugfixes.
Mark-Simulacrum
committed
Disable `mmap` in `libbacktrace` on Apple platforms

JohnColanduoni
authored and
Mark-Simulacrum
committed
Bump beta releasse number to generate a new compiler.
Mark-Simulacrum
committed