test verifier

function %gcd(i32 uext, i32 uext) -> i32 uext system_v {
    fn1 = %divmod(i32 uext, i32 uext) -> i32 uext, i32 uext

ebb1(v1: i32, v2: i32):
    brz v2, ebb2
    v3, v4 = call fn1(v1, v2)
    return v3

ebb2:
    return v1
}