[patch] Fix PR python/10646. Add libstdc++ Python pretty-printers for -D_GLIBCXX_DEBUG cases.

[Benjamin Kosnik]

> Benjamin> Is there any chance we can get some additions about using
> Benjamin> the python pretty-printers in the docs? I'm thinking on the
> Benjamin> main debug page (see debug.gdb in file
> Benjamin> doc/xml/manual/debug.xml), in the gdb section? I would also
> Benjamin> like to see some mention of this on the
> Benjamin> gcc-4.5/changes.html page, in the libstdc++ section.
> 
> Good idea, one of us will do this.

Cool. Don't know if libstdc++ docs are the place to put it, or if gdb
works better and we can just link to that.

Just briefly what it is, how to see if it's supported in gdb, how to
turn it on, how to turn it off. This was already in your blog, but I
think more central placement would be wise.

-benjamin