vk::image_format support missing from HLSL compile

[buzmeg]

The following code:

[[vk::image_format("rgba8")]] RWTexture2D<float4> isw;

fails with

warning: 'image_format' : unrecognized attribute

[arcady-lunarg]

As of right now, glslang HLSL support is not under active development, though there are occasionally bugfixes. We certainly won't say no to patches for new features, but it's up to the community to develop them.