NIR: Add truth table based logic ops
The idea here would be to add a set of probably three ALU ops which each take one, too, or three integer sources which are the actual input and another source which is an immediate which represents a truth table. The result of the op is computed by applying the truth table bitwise to the main sources. These should be a bit easier to combine than the separate logic ops.
On Intel Gen8+, we can implement any two-source logic op in one instruction thanks to sorce modifiers. On Panfrost, they have logic op which is basically exactly this.