RFC: add a testsuite for libstdc++ pretty-printers

[Tom Tromey]

Tom> * testsuite/libstdc++-pp/simple.cc: New file.
Tom> * testsuite/lib/gdb-test.exp: New file.
Tom> * testsuite/libstdc++-pp/pp.exp: New file.

Benjamin> feel free to spell out prettyprinters instead of using pp, if you want
Benjamin> to make it very obvious what is going on in this directory.

Benjamin> we really strive for clarity given that this testsuite is so large

Tom> No problem, I will do that.

I updated my patch for this.

These new tests require a very new gdb in order to fully pass.  In
particular these tests pointed out some buglets that are only fixed in
CVS, not in any release.


Trying to dynamically adjust the tests for the gdb version looks like a
pain.

Maybe I could change the tests to check the gdb version and xfail the
tests for gdb < 7.3.  Would that be ok?

Or I could leave it as-is, but I assume that nobody wants to see new
FAILs.

Tom