[PATCH 0/4] MR794: vkd3d-shader/hlsl: Improve SM1 support for non-float operations, part 6.

[Francisco Casas (＠fcasas)]

This should be the last piece of the puzzle for SNK games.

Basically, support for "if" conditionals for shader model 3.0 and 4.0.

This is achieved through the use of the `if_comp` instruction (VKD3DSIH_IFC), but these are not handled by the cf_flattener.
So I wrote `vsir_program_lower_ifc()` as a normalization pass to turn them into VKD3DSIH_IF in 3/4.
This requires translating the condition of IFC into a separate vsir comparison instruction. I think I got the mapping right in `get_handler_idx_from_rel_op()` but it would be good if someone with more experience in SPIR-V takes a close look.