Should we output input/output signatures for d3dbc shaders? Currently we do, and there's something to be said for that, but it does complicate things in a couple of ways: - We wouldn't be able to assemble such signatures in any meaningful way for d3dbc targets. I.e., the assembler would largely just have to ignore them. - The register names are slightly different. E.g. ps_2_0 has t# texture coordinate inputs and oC# colour outputs.