Rollup of 9 pull requests#66421

Closed

tmandry wants to merge 29 commits into

rust-lang:masterfrom

tmandry:rollup-l3oek9e

Commits on Oct 22, 2019

rename Error::iter_chain() and remove Error::iter_sources()
haraldh
committed

Commits on Nov 13, 2019

Do not ICE in `if` without `else` in `async fn`
estebank
committed

Commits on Nov 14, 2019