Define HLSL Matrix behavior

[pow2clk]

Leveraging existing support for clang matrices, enable compatible HLSL matrix support potentially with alterations consistent with the direction of the language. At the very least, the following design decisions are needed:

• Design mangling support to enable parameters and globals.
  • This will likely change some DXC overloading behavior e.g. float2x2 matching float4
• Initialization syntax consistent with changes from DXC
  • DXC allows flat scalar or vector initialization
• Allow broader type interactions likely through automatic conversions consistent with changes from DXC
• Allow boolean matrices
  • This may dovetail with expanding boolean and other vector type compatibility.