Rollup of 7 pull requests#63744

Merged

bors merged 14 commits intorust-lang:masterfrom

Centril:rollup-g4l3ra9

Aug 20, 2019

Commits on Aug 4, 2019

Implement nth_back for ChunksExactMut
JohnTitor
committed

Commits on Aug 6, 2019

avoid unnecessary reservations in std::io::Take::read_to_end
oconnor663
committed

Commits on Aug 18, 2019

Fix bug in iter::Chain::size_hint
timvermeulen
committed

Commits on Aug 19, 2019

Commits on Aug 20, 2019