test verifier

function %gcd(i32 uext, i32 uext) -> i32 uext system_v {
    fn0 = %divmod(i32 uext, i32 uext) -> i32 uext, i32 uext

ebb1(v0: i32, v1: i32):
    brz v1, ebb2
    v2, v3 = call fn0(v0, v1)
    return v2

ebb2:
    return v0
}