Rollup of 7 pull requests#84757

Closed

GuillaumeGomez wants to merge 18 commits intorust-lang:masterfrom

GuillaumeGomez:rollup-tkw84zs

Commits on Apr 28, 2021

unignore a couple of tests
mark-i-m
committed
added methods src_root and location to External crate, remove extern_location function
Timothée Delabrouille
committed

Commits on Apr 29, 2021

fix test
mark-i-m
committed
only store locations in extern_locations
Timothée Delabrouille
committed
platform-support.md: Update for consistency with Target Tier Policy
joshtriplett
committed
[Arm64] use isb instruction instead of yield in spin loops
Sebastian Pop
committed

Commits on Apr 30, 2021