== foo ==
fun foo(): Int {
    val t = x@ (1 + 2)
    return t
}
---------------------
1                                 <v0>: Int   NEW: r(1) -> <v0>
2                                 <v1>: Int   NEW: r(2) -> <v1>
1 + 2                             <v2>: Int   NEW: call(1 + 2, plus|<v0>, <v1>) -> <v2>
(1 + 2)                           <v2>: Int   COPY
x@ (1 + 2)                        <v2>: Int   COPY
t                                 <v3>: Int   NEW: r(t) -> <v3>
return t                          !<v4>: *
{ val t = x@ (1 + 2) return t }   !<v4>: *    COPY
=====================