FILE: invokeWithExtensionReceiver.kt
    public final fun foo(): R|kotlin/Unit| {
        lval ext: R|kotlin/String.(kotlin/Int) -> kotlin/Unit|
        lval usedReceiver: R|kotlin/String| = String(foo)
        lval unusedReceiver: R|kotlin/String| = String(bar)
        R|<local>/ext|.R|SubstitutionOverride<kotlin/Function2.invoke: R|kotlin/Unit|>|(R|<local>/usedReceiver|, Int(10))
    }