Rollup of 8 pull requests#87725

Merged

bors merged 17 commits into

rust-lang:masterfrom

JohnTitor:rollup-2ywcpuk

Aug 3, 2021

Commits on Jul 30, 2021

Commits on Aug 1, 2021

Write docs for SyncOnceCell From and Default impl
notriddle
committed

Commits on Aug 2, 2021

Add `aarch64-apple-ios-sim` as a possible target to the manifest
badboy
committed
Add convenience for handling ipv4-mapped addresses by canonicalizing them
the8472
committed

Commits on Aug 3, 2021