Changes to #[repr(simd)] in nightly break XYZ structs on SPIR-V targets

[Arc-blroth]

Since rust-lang/rust#80652, #repr(simd)] types on nightly Rust are now required to have a power-of-two size. This change breaks glam::core::storage::XYZ and everything that depends on it on SPIR-V targets:

error[E0075]: SIMD vector length must be a power of two
    --> .cargo\registry\src\github.com-1ecc6299db9ec823\glam-0.12.0\src\core\storage.rs:12:1
     |
  12 | / pub struct XYZ<T> {
  13 | |     pub x: T,
  14 | |     pub y: T,
  15 | |     pub z: T,
  16 | | }
     | |_^
  error: monomorphising SIMD type `XYZ<f32>` of non-power-of-two length

Whether or not non-power-of-two support for SIMD types is coming back is still being discussed, so it's possible that someone will re-add non-power-of-two support in the future. For now though, this issue would make it hard for downstream consumers like EmbarkStudios/rust-gpu to move to the latest nightly.

[bitshifter]

Thanks for the heads up @Arc-blroth!

[workingjubilee]

Whoops! Our bad.

Going to figure out how to fix this.