d3d12, microsoft/compiler, microsoft/spirv_to_dxil: Fix shader io locations on translator
Collection of changes to fix some issues with shader signatures.
- [d3d12, spriv_to_dxil] We are switching from semantics from GENERIC/VARYING to TEXCOORD, index. This change better aligns with other hlsl/dxil generators (SPIRV-Cross, Google's Tint).
- [d3d12, spriv_to_dxil] Use location instead of drive_location as the semantic index. This keeps the semantic index as it was specified in the shader.
- [spriv_to_dxil] Assign drive_location based on location (similar to D3D12 backend).