[Bug libstdc++/58962] Pretty printers use obsolete Python syntax

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58962

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.10.0                      |4.9.2

--- Comment #8 from Jonathan Wakely <redi at gcc dot gnu.org> ---
backported for 4.9.2