So, my idea is that Kotlin could generate the third variant for us, equivalent to an extension function:

fun SamJava.many(
        a: String,
        b: AccidentalSamInterface,
        c: AccidentalSamInterface,
        d: AccidentalSamInterface,
        e: () -> Unit
) {
    many(a, b, c, d, SamInterface(e))
}