rustc-ap-rustc_arena 722.0.0

Automatically published version of the package `rustc_arena` in the rust-lang/rust repository from commit c9c1f8be3fda5b58520c579451d3f5e20736ec90 The publishing script for this crate lives at: https://github.com/alexcrichton/rustc-auto-publish
Documentation
The arena, a fast but limited type of allocator. Arenas are a type of allocator that destroy the objects within, all at once, once the arena itself is destroyed. They do not support deallocation of individual objects while the arena itself is still alive. The benefit of an arena is very fast allocation; just a pointer bump. This crate implements several kinds of arena.