add typedef printers to libstdc++

[Paolo Carlini]

Hi Tom,

On 09/25/2012 10:53 PM, Tom Tromey wrote:
>>>>>> "Magnus" == Magnus Fromreide <magfr@lysator.liu.se> writes:
> Magnus> How does it display the types of the variables us, s and ss in the
> Magnus> following code:
>
> It does what you'd expect.
>
> Magnus> I would expect it to say std::basic_string<unsigned char,...>,
> Magnus> std::string and std::basic_string<signed char,...>, but I thought a test
> Magnus> case here couldn't hurt?
>
> Here's an updated patch with the new tests.
Jon knows the prettyprinters much better than me, but he is currently 
traveling. I guess, unless he has something to add over the next couple 
of days or so, let's go ahead.

Thanks!
Paolo.