Added tests with FilenameFilter (several arguments).

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

@@ -0,0 +1,9 @@
+import java.io.*
+
+fun box(): String {
+    val filter = FilenameFilter { dir, name -> if (name == null) false else (name as java.lang.String).endsWith(".md") }
+    val listFiles = File(".").listFiles(filter)!!
+    if (listFiles.size != 1) return "Wrong size: $listFiles.size"
+    val name = listFiles[0].getName()
+    return if (name == "ReadMe.md") "OK" else "Wrong name: $name"
+}