Rollup of 13 pull requests#88217

Merged

bors merged 28 commits intorust-lang:masterfrom

jackh726:rollup-3k74o2m

Aug 22, 2021

Commits on Aug 15, 2021

Update RELEASES to clarify attribute macro values.
ehuss
committed

Commits on Aug 16, 2021

Allow the iOS toolchain to be built on Linux
kit-981
committed

Commits on Aug 19, 2021

Commits on Aug 21, 2021

Test use of impl Trait in an impl as the value for an associated type in an impl trait
spastorino
committed
Test that incomplete inference for TAITs fail
spastorino
committed

Commits on Aug 22, 2021