[Feature] Handle absorbing constant propagation

[SirLynix]

Currently, constant propagation on binary expressions requires to know both operands, but there are cases than can be optimized when knowing only one operand:

• a + 0 -> a
• 0 + a -> a
• a - 0 -> a
• 0 - a -> -a
• -(-a) -> a
• 0 * a -> 0
• a * 0 -> 0
• 1 * a -> a
• a * 1 -> a
• a / 1 -> a (only with integers, because of NaN/inf)
• a / a -> 1 (only with integers, because of NaN/inf, no need to handle 0 / 0 as it's UB anyway)
• a && true -> a
• a && false -> false
• a || true -> true
• a || false -> a
• a < 0 -> false (only with unsigned integers)
• a >= 0 -> true (only with unsigned integers)
• a == NaN -> false
• a == a -> true (only with integers, because of NaN/inf)
• a != a -> false (only with integers, because of NaN/inf)
• x * po2 -> x << sqrt(po2)
• x / po2 -> x >> sqrt(po2)

This will become more important once function inlining is implemented.