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

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

@@ -0,0 +1,20 @@
+// This test was adapted from compiler/testData/codegen/box/callableReference/function/.
+package foo
+
+fun run(funRef:() -> String): String {
+    return funRef()
+}
+
+fun bar() = "OK"
+
+fun box(): String {
+    val x = ::bar
+
+    var r = x()
+    if (r != "OK") return r
+
+    r = run(::bar)
+    if (r != "OK") return r
+
+    return "OK"
+}