Rollup of 9 pull requests#88556

Merged

bors merged 21 commits intorust-lang:masterfrom

m-ou-se:rollup-q636wyd

Sep 1, 2021

Commits on Aug 15, 2021

Fix the flock fallback implementation
bjorn3
authored

Commits on Aug 18, 2021

BTree: remove Ord bound from new
nbdd0121
committed

Commits on Aug 26, 2021

add support for clobbering xer, cr, and cr[0-7] for asm! on OpenPower/PowerPC
programmerjake
committed

Commits on Aug 30, 2021

emit specific warning to clarify that foreign items can't have no_mangle
asquared31415
committed

Commits on Aug 31, 2021

Commits on Sep 1, 2021