Rollup of 6 pull requests#66452

Closed

Centril wants to merge 22 commits intorust-lang:masterfrom

Centril:rollup-p9c0a8b

Commits on Nov 9, 2019

Update cc, git2, num_cpus.
ehuss
committed

Commits on Nov 12, 2019

Commits on Nov 15, 2019