PR libstdc++/59476
	* python/libstdcxx/v6/printers.py (get_value_from_Rb_tree_node): New
	function to handle both C++03 and C++11 _Rb_tree_node implementations.
	(StdRbtreeIteratorPrinter, StdMapPrinter, StdSetPrinter): Use it.
	* testsuite/libstdc++-prettyprinters/simple.cc: Update comment to
	refer to...
	* testsuite/libstdc++-prettyprinters/simple11.cc: New.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@210008 138bc75d-0d04-0410-961f-82ee72b054a4