QTaggedPointer: Assert on the same tag value as we use in setTag()

If we assert on a different cast we may just get a different integer
value, if Tag is a sufficiently nefarious type.

Coverity-Id: 403056
Change-Id: I6e8e3883bce124b3350ad8276d88ac7ed030d982
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qtaggedpointer.h

@@ -104,8 +104,10 @@ public:
 
     void setTag(Tag tag)
     {
-        Q_ASSERT_X((static_cast<typename QtPrivate::TagInfo<T>::TagType>(tag) & pointerMask()) == 0,
-            "QTaggedPointer<T, Tag>::setTag", "Tag is larger than allowed by number of available tag bits");
+        Q_ASSERT_X(
+                (static_cast<quintptr>(tag) & pointerMask()) == 0,
+                "QTaggedPointer<T, Tag>::setTag",
+                "Tag is larger than allowed by number of available tag bits");
 
         d = (d & pointerMask()) | static_cast<quintptr>(tag);
     }