Add testcases for on-demand .prototype

Author: svaarala

tests/ecmascript/test-dev-ondemand-constructor-prototype-1.js

@@ -0,0 +1,72 @@
+/*---
+{
+    "custom": true
+}
+---*/
+
+function FX() {
+    print('finalize X');
+}
+function FY() {
+    print('finalize Y');
+}
+
+print('- prototype in func');
+var f = function () {};
+print('prototype' in f);
+Duktape.gc(); Duktape.gc();
+
+print('- own property names');
+var f = function () {};
+print(Object.getOwnPropertyNames(f).join(','));
+f.prototype.foo = 'bar';
+print(Object.getOwnPropertyNames(f).join(','));
+Duktape.gc(); Duktape.gc();
+
+print('- refcount finalization, anonymous function');
+var X = function () {};
+Duktape.fin(X, FX);
+print('setting X to null');
+X = null;
+print('X set to null');
+Duktape.gc(); Duktape.gc();
+
+print('- refcount finalization, named function');
+var X = function foo() {};
+Duktape.fin(X, FX);
+print('setting X to null');
+X = null;
+print('X set to null');
+Duktape.gc(); Duktape.gc();
+
+print('- refcount finalization, anonymous inner function, reference not kept');
+var X = function () {
+    var Y = function () {};
+    Duktape.fin(Y, FY);
+    Y = null;
+};
+Duktape.fin(X, FX);
+print('call X');
+X();
+print('setting X to null');
+X = null;
+print('X set to null');
+Duktape.gc(); Duktape.gc();
+
+print('- refcount finalization, anonymous inner function, reference kept');
+var X = function () {
+    var Y = function () {};
+    Duktape.fin(Y, FY);
+    // At this point the anonymous inner function points to the outer scope,
+    // which holds a reference back to the function via 'Y', so cannot
+    // collect via refcounting.
+};
+Duktape.fin(X, FX);
+print('call X');
+X();
+print('setting X to null');
+X = null;
+print('X set to null');
+Duktape.gc(); Duktape.gc();
+
+print('done');