Backport raw-window-handle v0.6 support to wgpu v0.18

[daxpedda]

I was wondering if it would be possible to add support for raw-window-handle v0.6, see #4202, to wgpu v0.18.

As far as I can see, it's unfortunately not possible anymore to remove the dependency on raw-window-handle v0.5, because it wasn't marked optional, doing that now would be a breaking change.

My proposal would be to add a new crate feature to enable support for raw-window-handle v0.6.

I've already put together something working here: daxpedda/wgpu@v0.18...daxpedda:wgpu:raw-window-handle-v0.6. I'm happy to make a PR, but would require a new v0.18 branch to target it against.

[cwfitzgerald]

With winit supporting RWH 0.5, is this really worth the bother?

[pzipper]

With winit supporting RWH 0.5, is this really worth the bother?

Winit 0.29 seems to use RWH 0.6 by default, and RHW 0.5 must be enabled with a feature flag

[daxpedda]

After some thinking on this I agree that this doesn't make sense.

• We can't change the type of Surface to implement safe surface creation.
• We can't make RWH v0.5 optional so the dependency will be there anyways.

The only advantage I see is for compatibility with other types/libraries that only support RWH v0.6, which personally I have no horse in, as e.g. Winit has compatibility for both.

Therefor I'm closing this.