PR59170 make pretty printers check for singular iterators
PR libstdc++/59170
* python/libstdcxx/v6/printers.py (StdListIteratorPrinter.to_string)
(StdSlistIteratorPrinter.to_string, StdVectorIteratorPrinter.to_string)
(StdRbtreeIteratorPrinter.to_string)
(StdDequeIteratorPrinter.to_string): Add check for value-initialized
iterators.
* testsuite/libstdc++-prettyprinters/simple.cc: Test them.
* testsuite/libstdc++-prettyprinters/simple11.cc: Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@243692 138bc75d-0d04-0410-961f-82ee72b054a4