97678b8358
Inline Default::default() for atomics
Functions like `AtomicUsize::default()` are not cross-crate inlineable before this PR ([see assembly output here](https://play.rust-lang.org/?version=stable&mode=release&edition=2018&gist=e353321766418f759c69fb141d3732f8)), which can lead to unexpected performance issues when initializing a large array using this function, e.g. as seen [here](d513996a85/src/histogram.rs (L53)) which should turn into a simple loop writing zeroes but doesn't.
r? @m-ou-se