RFC: unary operations

[andres-erbsen]

I will probably need to add unary bitwise negation for MSVC -WError compatibility; a "-1" literal isn't allowed there. Probably best to desugar in the flattening phase?

[samuelgruetter]

Yeah, the flattening phase could emit SOp resVar bopname.xor argVar argVar for unary bitwise negation. Or if you want a cheaper solution, you could also just define bitwiseNeg x := expr.xor x x at the source level in bedrock2.Syntax, there's already enough precedent for that 😉