Test for use of staging buffer in writeTexture

[andyleiserson]

Test a writeTexture operation that will use the staging buffer. This fails if run under the address sanitizer without the fix for #7893. (Running under asan requires the test enumeration change from #7940.)

Fixes #7894

Testing
Verified regression test fails without the associated fix.

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.

[cwfitzgerald]

Nice! Asan support would be cool - is there a good primer on getting that set up, would be nice to run CI under ASAN

[cwfitzgerald]

nit, all important things are re-exported from wgpu - here you should do use wgpu::*

[andyleiserson]

I used this command to run the gpu-tests suite with asan:

RUSTFLAGS="-Z sanitizer=address" cargo +nightly nextest run -Z build-std -p wgpu-test --target aarch64-apple-darwin

I also tried the CTS CI test list. The only thing I found from either is the stack trace I posted to the metal null pointer issue, which it sounds like may not be specific to asan.

[cwfitzgerald]

Nice - I might see if I can get that rolling in CI