Import revision 49281 from the v5-34-00 patch branch:
Repair support for std::bitset.  It has no iterator and we can not
access the element by address, so we need to treat it the same way
we treat the associative container (cache the input into an array
of bool and use the 'feed' function.


git-svn-id: https://root.cern.ch/svn/root/trunk@49283 27541ba8-7e3a-0410-8455-c3a389f83636