Norihiro Tanaka wrote:
> I thought of various things for the name of the function, but I could
> not think of a good name.

Yes, that's a tough one. I eventually came up with maybe_disable_superset_dfa. 
Perhaps we can think of an ever better one.

I installed your patches into Gnulib, along with the attached relatively-minor 
fixups, and then propagated the result into grep by updating the Gnulib version 
that the grep master points to.

As you may notice, nowadays I prefer using signed types like ptrdiff_t to 
unsigned ones like size_t, as the signed types have a significant advantage in 
overflow checking with gcc -fsanitize=undefined. Perhaps at some point we should 
change the other instances of size_t in dfa.c, but one step at a time.

Thanks again for the performance improvement.