printers.py (StdExpAnyPrinter.__init__): Strip typename versioned namespace before the substitution.

2017-11-01  François Dumont  <fdumont@gcc.gnu.org>

	* python/libstdcxx/v6/printers.py (StdExpAnyPrinter.__init__): Strip
	typename versioned namespace before the substitution.
	(StdExpOptionalPrinter.__init__): Likewise.
	(StdVariantPrinter.__init__): Likewise.
	(Printer.add_version): Inject versioned namespace after std or
	__gnu_cxx.
	(build_libstdcxx_dictionary): Adapt add_version usages, always pass
	namespace first and symbol second.

From-SVN: r254320