Element masks can have a left shift in DXIL, but these must start at
bit 0 in the register info. The SPIR-V declaration will either be a
builtin or have SpvDecorationComponent.
We want to be able to remap input signatures based on the signature index, but
signature normalization both reorders the signature, and requires the old
register index, so add a new field for this.
Store it in the shader_desc, and declare temps from that when compiling SPIR-V,
instead of parsing dcl_instructions.
As part of this change, we declare a single, global temps array (with Private
scope instead of Function) which is as large as the maximum of all dcl_temps
instructions. It is not clear to me whether this will improve, hurt, or have no
significant effect on the lower-level compiler. An alternative is to still
redeclare a new temps array every time (although still with a smaller size).
This only affects clip and cull distances. The HLSL compiler emits these using
dcl_input, but the previous shader (vertex or TES) will write them as a SPIRV
builtin, and hence we want to read this as a SPIRV builtin as well.
This fixes validation errors in Wine's test_clip_distance().
