Re: [PATCH 0/1] MR349: vkd3d-shader/spirv: Ensure that all instructions belong to a block.

[Conor McCarthy (＠cmccarthy)]

I think the backend should reject shaders with instructions outside blocks, except perhaps `nop`. A valid vsir shader should also contain no instructions outside blocks. Validating that in TPF is too complicated, but this touches on an issue which will arise in DXIL when branch and switch instructions are added. Using the same vsir instructions for both SM4/5 and SM6 shaders would require handling the SM4/5 structured control flow instructions in a normalisation stage, which would perform all validations.