qcssparser: Undef TILDE to fix compilation on Hurd

Change-Id: Ic3168629565618bcd7f26e47579beaa1bbd22e39
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

src/gui/text/qcssparser_p.h

@@ -75,6 +75,10 @@ QT_END_NAMESPACE
 #if defined(Q_OS_INTEGRITY)
 #  undef Value
 #endif
+// Hurd has #define TILDE 0x00080000 from <sys/ioctl.h>
+#if defined(TILDE)
+#  undef TILDE
+#endif
 
 #define QT_CSS_DECLARE_TYPEINFO(Class, Type) \
     } /* namespace QCss */ \