[DirectX] Design and implement TableGen specification of DXIL operation attributes

[bharadwajy]

Design and implement a format to specify following DXIL Operations attributes as defined in hctdb.py in their corresponding TableGen records

• fn_attr - Attribute shorthand strings: rn=does not access memory,ro=only reads from memory,
• is_deriv - Bool indicating whether this is some kind of derivative
• is_gradient - Bool indicating whether this requires a gradient calculation
• is_feedback - Bool indicating whether this is a sampler feedback op
• is_wave - Bool indicating whether this requires in-wave, cross-lane functionality
• requires_uniform_inputs - Bool indicating whether this operation requires that all of its inputs are uniform across the wave
• is_barrier - Bool indicating whether this is a barrier operation
• shader_stages - shader stages to which this applies, empty for all.
• is_reserved - Bool that evaluates (dxil_class == "Reserved")
• shader_model_translated - minimum shader model required with translation by linker
• props - extra properties

Implement the functionality in TableGen backend, DXILEmitter, to generate necessary C++ data structures and/or tables for lowering passes to consume the attribute information.

[bharadwajy]

At present, DXIL.td is intended to contain DXIL attributes necessary for DXIL backend passes. The DXIL Operation attributes listed are not expected to be necessary for the functionality of DXIL backend passes. Hence work on this issue is not planned.

[bharadwajy]

Design completed #95807. Implementation is tracked by #91492