test compile
target x86_64

function u0:0(i8) -> i8 fast {
ebb0(v0: i8):
    v1 = iconst.i8 0
    v2 = isub v1, v0
    ; check: v4 = uextend.i32 v0
    ; nextln: v6 = iconst.i32 0
    ; nextln = isub v6, v4
    ; nextln = ireduce.i8 v5
    return v2
}