JS backend: testFiles -> testData

js/js.translator/testData/expression/invoke/cases/invokeMethod.kt

@@ -0,0 +1,12 @@
+package foo
+
+class Foo(val postfix: String) {
+    public fun invoke(text: String): String {
+        return text + postfix
+    }
+}
+
+fun box(): String {
+    val a = Foo(" world!")
+    return a("hello")
+}