PR #987

PR #992

Otherwise it's possible for the fuzzer to build a regex that is big
enough to timeout on a big haystack.

The fuzzer keeps finding regexes that just fit into the limit, have a
Unicode word boundary assertion and gives a decent sized haystack. This
in turn results in slowish searches. The searches are horrificly slow,
but they become much slower with the sanitizers enabled it looks like.

So... drop the size limit down even more.

This fixes a bug where the calculation for the min/max length of a regex
could overflow if the counted repetitions in the pattern are big enough.
The panic only happens when debug assertions are enabled, which means
there is no panic by default in release mode.

One may wonder whether other bad things happen in release mode though,
since in that case, the arithmetic will wrap around instead. Since this
is in new code and since the regex crate doesn't yet utilize the min/max
attributes of an Hir, the wrap around in this case is completely
innocuous.

Fixes #995