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

js/js.translator/testData/box/callableReference/function/extensionFromTopLevel.kt

@@ -0,0 +1,27 @@
+// This test was adapted from compiler/testData/codegen/box/callableReference/function/.
+package foo
+
+fun <T> run(arg1: A, arg2: T, funRef:(A, T) -> T): T {
+    return funRef(arg1, arg2)
+}
+
+class A {
+    var xx: Int = 100
+}
+
+fun A.bar(x: Int): Int {
+    this.xx = this.xx * 2
+    return x
+}
+
+fun box(): String {
+    val funRef = A::bar
+    val obj = A()
+    var result = funRef(obj, 25)
+    if (result != 25 || obj.xx != 200) return "fail1: result = $result, expected 25; obj.xx = $obj.xx, expected 200"
+
+    result = run(A(), 25, funRef)
+    if (result != 25 || obj.xx != 200) return "fail2: result = $result, expected 25; obj.xx = $obj.xx, expected 200"
+
+    return "OK"
+}