+- [The layout of `repr(Rust)` types now groups m\*2^n-sized fields with
+ equivalently aligned ones.](https://github.com/rust-lang/rust/pull/102750/)
+ This is intended to be an optimization, but it is also known to increase type
+ sizes in a few cases for the placement of enum tags. As a reminder, the layout
+ of `repr(Rust)` types is an implementation detail, subject to change.