LoadOp::DontCare

[cwfitzgerald]

Description

For native users who are always writing to all of their render target, this will provide the best performance on all hardware without needing to switch between Clear/Load depending on if they're running on a tiler or not.

I've also refactored wgpu-hal to actually have bitflags for all the variants, instead of having "no flags" have a special meeting.

Testing

Test pass. Going to add a test for DontCare before this is ready for review.

Squash or Rebase?

Squash

Checklist

• Run cargo fmt.
• Run taplo format.
• Run cargo clippy --tests. If applicable, add:
  • --target wasm32-unknown-unknown
• Run cargo xtask test to run tests.
• If this contains user-facing changes, add a CHANGELOG.md entry.