Remove clones in step operations

[gabrielbosio]

Line 336 clones every Res::Op1 case:

Res::Op1 => Ok(Some(op1.clone()))

Line 349 clones every AssertEq:

(Opcode::AssertEq, Some(res)) => res.clone()

Lines 680 and 3227-3230 clone operand deductions:

Some(op0.clone())

We should replace each clone with references or restructure to avoid cloning.

Measure performance improvement of this change.