This commit fixes an amazing number of new typos that I introduced in
the regex 1.9 release.

The typos were found and fixed by the typos-cli tool.[1]

[1]: https://crates.io/crates/typos-cli

PR #1026

This new fuzzer program caught a timeout. It looks mostly uninteresting.
It's basically the result of a huge regex running on a decently sized
haystack that is forced to use the PikeVM. The PikeVM is slow. We know
that.

Ref https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=60402

This fixes a memory usage regression where the backtracker would eagerly
allocate its entire capacity up-front. In this case, it meant a minimum
of 256KB for every regex.

Prior to regex 1.9, 256KB was treated as a *maximum*, and we only
allocated what we needed. We migrate that strategy to regex-automata now
as well. This probably does come with a latency cost (I'll run rebar to
be sure it isn't horrendous), but we definitely can't be eagerly
allocating 256KB for every regex. If the latency ends up being an issue,
we can investigate fixing that in other ways.

Fixes #1027