[DXIL] Remove use of `Property` in `DXIL.td` and its generation

[inbelic]

Previously, we had copied over the idea of a Property or Attribute from DXC to DXIL.td, which would group together a sub-set of DXIL ops. For example, IsWave or IsGradient.

The intention had been to group like ops in DXIL.td that could then be used for various forms of analysis, a primary use-case would be for Shader Flag analysis. This would be beneficial if DXIL.td was still intended as a place to define all DXIL op related information.

In practice when implementing wave op shader flag analysis, having the definitions of Wave ops separately in DXIL.td and creating a mapping back to the definitions proves less intuitive then having the relevant ops listed in a simple switch statement.

Finally, from a brief look at DXC, there appears to be very limited current use-cases of IsWave or the other properties in analysis.

Since:

• There is almost no other current analysis uses of the IsWave or equivalents
• Having the definitions elsewhere from the use creates unnecessary complexity
• DXIL.td is no longer intended to be a complete reference of all DXIL information

Then, we can propose to remove this from DXIL.td and its uses.