Rollup of 7 pull requests#64026

Merged

bors merged 20 commits intorust-lang:masterfrom

Centril:rollup-le667lp

Aug 31, 2019

Commits on Aug 6, 2019

Match the loop examples
dns2utf8
committed

Commits on Aug 18, 2019

Constify LinkedList new function
GrayJack
committed

Commits on Aug 25, 2019

Fix system theme detection
GuillaumeGomez
committed

Commits on Aug 29, 2019

Commits on Aug 30, 2019