fold-reductions with || and && are not lazy!
Extended Description
This is probably two bug reports:
1. "fold" does not quick-stop on relational functions, once it
has determined that the result can no longer change. For example:
or-reduce boolean, once it finds a true.
and-reduce boolean, once it finds a false.
times-reduce, once it finds a zero.
As a result of this, I can't use "fold" in practice for relational
reductions, as its performance is dismal. Note that changing
the first/last elements of bv to "true" makes no difference in fold
performance.
So, I tried a for-loop, but its performance is even worse.
See testfoldwith.sac
2. for-loop performance is about 10x worse than that of a with-loop.
See testfoldfor.sac.
