Kill qHash(QPointF)

QPointF operator== is fuzzy, hence it can't be hashed efficiently.
Prevent the erroneous addition of the overload by client code
by providing it as deleted.

Change-Id: I2cfaaf5c2c8896ec9a7929f7c7bf52a912d0450f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qpoint.h

@@ -328,6 +328,8 @@ private:
 
 Q_DECLARE_TYPEINFO(QPointF, Q_RELOCATABLE_TYPE);
 
+size_t qHash(QPointF, size_t seed = 0) = delete;
+
 /*****************************************************************************
   QPointF stream functions
  *****************************************************************************/