Supported functional interfaces with generic parameters in codegen.

compiler/testData/codegen/box/sam/comparator.kt

@@ -0,0 +1,8 @@
+import java.util.*
+
+fun box(): String {
+    val list = ArrayList(Arrays.asList(3, 2, 4, 8, 1, 5))
+    val expected = ArrayList(Arrays.asList(8, 5, 4, 3, 2, 1))
+    Collections.sort(list, Comparator { a, b -> b - a })
+    return if (list == expected) "OK" else list.toString()
+}