JVM_IR indy-SAM: KT-45069 box lambda 'Unit' return type if needed

compiler/testData/codegen/box/invokedynamic/sam/specializedGenerics/genericWithInProjection.kt

@@ -0,0 +1,18 @@
+// TARGET_BACKEND: JVM
+// JVM_TARGET: 1.8
+// SAM_CONVERSIONS: INDY
+
+fun interface Cmp<T> {
+    fun compare(a: T, b: T): Int
+}
+
+fun <T> foo(comparator: Cmp<in T>, a: T, b: T) = comparator.compare(a, b)
+
+fun bar(x: Int, y: Int) = foo({ a, b -> a - b}, x, y)
+
+fun box(): String {
+    val t = bar(42, 117)
+    if (t != -75)
+        return "Failed: t=$t"
+    return "OK"
+}