new regexp library

[Stephen Weeks]

> I don't understand how it could have sped up mlprof by much since the only
> thing mlprof is now looking at is the output of the nm command.  I did notice
> a while ago that when profiling, the assembler is called with flags to retain
> debugging symbols.  This used to be needed, but I don't think it is any more.

It's been turned off (you can confirm by compiling -v -p).

> Even with that, I don't think that the output (of nm) should be very large at
> all.

Here is the size of the nm output for this particular test.

% nm -n z | wc
8733   26158  489400

There are 1-3 regexp matches per line.

I'm not sure whether that explains it or not.  The only other change was the
elimination of some of my other library code.  Anyways, I don't really care --
the point is it is now very fast.  Even better, the new 1 second number included
the regexp compilation time, which is 0.16s.