[Bug libstdc++/122156] [16 regression] qtbase-6.10.0rc tests fail to build

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122156

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
QTaggedIterator does not define a operator[] but that is required for random
access iterators.