Guillaume Gomez 53af11651b
Rollup merge of #80022 - ssomers:btree_cleanup_8, r=Mark-Simulacrum
BTreeSet: simplify implementation of pop_first/pop_last

…and stop it interfering in #79245.
r? ```````@Mark-Simulacrum```````
2020-12-17 11:36:49 +01:00
..
2020-09-29 21:39:24 +08:00