Got rid of "jet" file extension.

js/js.translator/testFiles/expression/function/cases/closureWithParameterAndBoxing.kt

@@ -0,0 +1,9 @@
+package foo
+
+fun box() : String {
+    return if (apply( 5, {(arg: Int) -> arg + 13 } ) == 18) "OK" else "fail"
+}
+
+fun apply(arg : Int, f :  (p:Int) -> Int) : Int {
+    return f(arg)
+}