Rollup of 4 pull requests - #59657

Merged

bors merged 9 commits into

rust-lang:masterfrom

Centril:rollup-w5p98mc

Apr 3, 2019

Commits on Mar 11, 2019

Add initial implementation of 'sort_at_index' for slices -- analog to C++'s std::nth_element (a.k.a. quickselect)
Mokosha
committed
3f306db

Commits on Mar 29, 2019

improve worst-case performance of BTreeSet difference and intersection
ssomers
committed
f5fee8f

Commits on Apr 2, 2019

Replace adt_def with name in mir::ProjectionElem::Downcast
tmandry
committed
ac29ca7
Remove adt_def from PlaceTy and make it a struct
tmandry
committed
4122d22
Shrink `mir::Statement`.
nnethercote
committed
d00d639

Commits on Apr 3, 2019