When promoting a float induction to an integer one, we already proven

that all possible vales will be integers that can be converted back to

floats.

This makes fp -> int conversions of the float induction variable

redundant. Instead of unconditionally replacing all uses of the float

induction with a int -> fp conversion of the integer induction, simplify

fp -> int conversion to the integer induction directly.

Doing this in other passes would be a bit more tricky, as we would need

to prove the restricted range of the integer induction again separately.

Fixes #55505.