Returning `true` is wrong here as we could have
the error diagnosed by another fix, which if not
handled, would lead to us crashing as we assume
we diagnosed the issue. Instead, return `false`,
allowing us to at least bail with a bad error
rather than a crash.
We still need to go through and update argument
list diagnostic logic to handle patterns, but I'm
leaving that as future work for now.
rdar://107724970
rdar://107651291
