Rollup of 7 pull requests - #63744

Merged

bors merged 14 commits into

rust-lang:masterfrom

Centril:rollup-g4l3ra9

Aug 20, 2019

Commits on Aug 4, 2019

Implement nth_back for ChunksExactMut
JohnTitor
committed
d3019d1

Commits on Aug 6, 2019

avoid unnecessary reservations in std::io::Take::read_to_end
oconnor663
committed
edb5214

Commits on Aug 18, 2019

Fix bug in iter::Chain::size_hint
timvermeulen
committed
ec54340

Commits on Aug 19, 2019

Don't use stage naming in RUSTFLAGS environment variables
Mark-Simulacrum
committed
9b3f072
Consolidate sigemptyset workarounds
josephlr
committed
8e91dca

Commits on Aug 20, 2019