spv-out: implement OpArrayLength on array buffer bindings

[kvark]

Fixes gfx-rs/wgpu#4556

[jimblandy]

Rebased to get rid of changes to irrelevant snapshot files

[jimblandy]

I think the back/spv changes can be simplified; see the earlier comments.

[kvark]

@jimblandy please take a look at the comments, PR is rebased

[kvark]

@jimblandy ready for round 3
Amazing review, as always, and thanks for the insights!

[JMS55]

Thanks so much for the work on this! Any chance it can be rebased to naga main?

[cwfitzgerald]

Hello, thank you for your PR against Naga!

As part of gfx-rs/wgpu#4231, we have moved development of Naga into the wgpu repository in the Naga subfolder. We have transferred all issues, but we are unable to automatically transfer PRs.

As such, please recreate your PR against the wgpu repository. We apologize for the inconvenience this causes, but will make contributing to both projects more streamlined going forward.

We are leaving PRs open, but once they are transferred, please close the original Naga PR.

[kvark]

Ported as gfx-rs/wgpu#5428