PR c++/16240

[Ian Lance Taylor]

Mark, I would like to draw your attention to PR c++/16240, as I think
it is a bug in the way in which g++ implements the C++ mangling ABI.

It showed up initially as a demangler bug, in that the demangler was
crashing on an error condition.  I've fixed the demangler to exit
cleanly rather than crash.  However, I believe that the name is
incorrectly mangled, which leaves us with an ABI problem.

I would be happy to hear otherwise.

Ian