[patch] handle nested exceptions

[Tom Tromey]

>>>>> "Doug" == Doug Evans <dje@google.com> writes:

Doug> How's this?
Doug> 2011-12-15  Doug Evans  <dje@google.com>

Doug>         * exceptions.c (catcher_list_size): New function.
Doug>         (last_message): Delete.
Doug>         (exception_messages, exception_messages_size): New static globals.
Doug>         (throw_it): Use exception_messages array to handle nested calls.

Looks good to me.  Thanks for updating that.

Tom