JS: create new common directory for all generated tests, migrate several tests there

js/js.translator/testData/box/extensionFunction/extensionFunctionCalledFromFor.kt

@@ -0,0 +1,34 @@
+package foo
+
+class SimpleEnumerator {
+    private var counter = 0
+
+    fun getNext(): String {
+        counter++;
+        return counter.toString()
+    }
+
+    fun hasMoreElements(): Boolean = counter < 1
+}
+
+class SimpleEnumeratorWrapper(private val enumerator: SimpleEnumerator) {
+    operator fun hasNext(): Boolean = enumerator.hasMoreElements()
+
+    operator fun next() = enumerator.getNext()
+}
+
+operator fun SimpleEnumerator.iterator(): SimpleEnumeratorWrapper {
+    return SimpleEnumeratorWrapper(this)
+}
+
+fun box(): String {
+    var o = ""
+    val enumerator = SimpleEnumerator()
+    for (s in enumerator) {
+        o += s;
+    }
+
+    if (o != "1") return "fail: $o"
+
+    return "OK"
+}