Rollup of 6 pull requests#68852

Closed

Centril wants to merge 25 commits intorust-lang:masterfrom

Centril:rollup-llumsuo

Commits on Jan 30, 2020

Commits on Feb 2, 2020

Strip unnecessary subexpression
ForNeVeR
authored

Commits on Feb 3, 2020

Commits on Feb 4, 2020

Clean up E0264, E0267 and E0268 explanations
GuillaumeGomez
committed

Commits on Feb 5, 2020