Add greater or equal symbol for numbers

I feel it is sometime clearer to write x ≥ y than y ≤ x in certain specific cases such as

match order with
 | Lt => x < y
 | Le => x ≤ y
 | Gt => x > y
 | Ge => x ≥ y
end

So I added ≥ as an infix for the numbers, as well as (>) and (≥)

If that feeling is not shared, I'm happy to keep those for my own developments.