gdb pretty-printers for libstdc++

[Tom Tromey]

>>>>> "Chris" == Chris Fairles <chris.fairles@gmail.com> writes:

Chris> What about printing std(::tr1)::tuple's? Might be hard since
Chris> the impl uses inheritance hierarchies.

I'll look into it.  In some cases, if the default looked ok, I did not
write a pretty-printer.  I don't recall whether this was the case for
tuple.

FYI we do have a known hole with pretty-printing base classes in gdb.
We'll be fixing this soon, and in any case it doesn't affect the
printers themselves.

Tom