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

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

@@ -0,0 +1,21 @@
+// This test was adapted from compiler/testData/codegen/box/callableReference/function/.
+package foo
+
+fun run(arg1: A, funRef:A.() -> String): String {
+    return arg1.funRef()
+}
+
+class A
+
+fun A.foo() = "OK"
+
+fun box(): String {
+    val x = A::foo
+    var r = x(A())
+    if (r != "OK") return r
+
+    r = run(A(), A::foo)
+    if (r != "OK") return r
+
+    return "OK"
+}