Auto merge of #155385 - davidtwco:stdarch-sync-160426, r=davidtwco

stdarch subtree update

Subtree update of `stdarch` to https://github.com/rust-lang/stdarch/commit/095646219d35769f013c4a54d843a982c87d979c.

Created using https://github.com/rust-lang/josh-sync.

r? @ghost