test verifier

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

block1(v0: i32, v1: i32):
    brz v1, block3
    jump block2

block2:
    v2, v3 = call fn0(v0, v1)
    return v2

block3:
    return v0
}