[MooreToCore] Lower moore operators into comb or hw.

[hailongSun2000]

Aim to lower moore elementary operators into comb or hw, excluding assignments and variable declarations. The latter needs to analyze the entire IR to map variables and their values. And moore without mux(? :), which is substituted by scf.if.
The elementary operators include unary, binary, relational, shift, constant, concatenation, extract, and conversion operations.
The moore.extract operation receives a variable as its operand, but comb.extract does not. I asked @fabianschuiki for help. He taught me maybe I could use comb.shr to bring a variable down to bit position 0, and then capture the correct number of bits from 0 with comb.extract.

[hailongSun2000]

Thanks for the code review in advance! ❤️

[fabianschuiki]

Looks good to me once BoolCastOpConversion returns failure() in case the operand isn't a simple bit vector 😃. Thanks for adding these conversions! Really cool to see SV get a path into the core dialects.

[hailongSun2000]

Looks good to me once BoolCastOpConversion returns failure() in case the operand isn't a simple bit vector 😃. Thanks for adding these conversions! Really cool to see SV get a path into the core dialects.

It's an honor for me to participate in this! 😄