[SMT-COMP] SMT-COMP benchmarks

[Clark Barrett]

As promised, new benchmarks that are eligible for the competition were posted
to the SMT-LIB website on May 1.  Please take a look at them and let us know if
you find any problems.

We know of a few benchmarks that are still coming (in particular, in the
bitvector division, which has relatively few difficult benchmarks), so we are
considering extending the deadline for submitting benchmarks to May 15.  We
will post any new submitted benchmarks by May 20.  We anticipate still being
able to meet our goal of finalizing all competition benchmarks by June 1.

Because this is a change in the timeline, please let us know if you think it is
unfair or object to this extension for some reason.  Also, if you have
additional benchmarks that you would like to submit by May 15, please let us
know.

Sincerely,
The SMT-COMP organizers