JS: add test with undeclared nested access

javascript/ql/test/library-tests/Closure/NestedAccess.ql

@@ -0,0 +1,3 @@
+import javascript
+
+select Closure::moduleImport("foo.bar.x.y.z")

javascript/ql/test/library-tests/Closure/tests/nestedAccess.js

@@ -0,0 +1,12 @@
+goog.module('enumuse');
+
+let fooBar = goog.require('foo.bar');
+
+fooBar.x.y.z;
+
+function infinite() {
+  let z = fooBar;
+  while (z) {
+    z = z.x;
+  }
+}