Rollup of 9 pull requests#64216

Closed

Centril wants to merge 22 commits intorust-lang:masterfrom

Centril:rollup-5cc1w7o

Commits on Sep 1, 2019

Remove no-prefer-dynamic from valgrind tests
Mark-Simulacrum
committed

Commits on Sep 2, 2019

Commits on Sep 3, 2019

Update test stderr with results of enabling unused lints
Mark-Simulacrum
committed

Commits on Sep 4, 2019

Commits on Sep 6, 2019