Remove superfluous assert when traversing IR

When accessing/calling a property on an object, it is possible (and
perfectly fine) for that object to be a constant value. I.e. Undefined.
All code handling such a call do handle constants correctly.

Note: this is a 5.9 specific change, because 5.11 got rid of this code.

Task-number: QTBUG-66027
Change-Id: Ied9d0c9c8f8bf958f8634f7be196900b3ea64861
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

src/qml/compiler/qv4isel_p.cpp

@@ -259,7 +259,6 @@ void IRDecoder::visitExp(IR::Exp *s)
         } else if (c->base->asTemp() || c->base->asArgLocal() || c->base->asConst()) {
             callValue(c->base, c->args, 0);
         } else if (Member *member = c->base->asMember()) {
-            Q_ASSERT(member->base->asTemp() || member->base->asArgLocal());
 #ifndef V4_BOOTSTRAP
             Q_ASSERT(member->kind != IR::Member::MemberOfIdObjectsArray);
             if (member->kind == IR::Member::MemberOfQmlScopeObject || member->kind == IR::Member::MemberOfQmlContextObject) {

tests/auto/qml/qqmlecmascript/tst_qqmlecmascript.cpp

@@ -339,6 +339,7 @@ private slots:
     void singleBlockLoops();
     void qtbug_60547();
     void anotherNaN();
+    void callPropertyOnUndefined();
 
 private:
 //    static void propertyVarWeakRefCallback(v8::Persistent<v8::Value> object, void* parameter);
@@ -8281,6 +8282,18 @@ void tst_qqmlecmascript::anotherNaN()
     object->setProperty("prop", d);  // don't crash
 }
 
+void tst_qqmlecmascript::callPropertyOnUndefined()
+{
+    QJSEngine engine;
+    QJSValue v = engine.evaluate(QString::fromLatin1(
+            "function f() {\n"
+            "    var base;\n"
+            "    base.push(1);"
+            "}\n"
+    ));
+    QVERIFY(!v.isError()); // well, more importantly: this shouldn't fail on an assert.
+}
+
 QTEST_MAIN(tst_qqmlecmascript)
 
 #include "tst_qqmlecmascript.moc"