Merge ref '9bb55c8c8654' from rust-lang/rust

Pull recent changes from https://github.com/rust-lang/rust via Josh.

Upstream ref: rust-lang/rust@9bb55c8c865411b7d9dea6ff743e583d510d89f5
Filtered ref: rust-lang/miri@89242b068d96ff312099ae2b3b9f92fc25c71801
Upstream diff: https://github.com/rust-lang/rust/compare/c656540d6467dee1381f0cbd882412d6bd1cd5ae...9bb55c8c865411b7d9dea6ff743e583d510d89f5

This merge was created using https://github.com/rust-lang/josh-sync.