swift234

Improve on how final release is found.

Improve when to bail while finding the final releases.

The ConsumedArgToEpilogueReleaseMatcher finds the final releases
in the following way.

1. If an instruction, which is not releaseinst nor releasevalue, that
could decrement reference count is found. bail out. This may well be the
real epilogue release.

2. If a release is found and the release that can not be mapped to any
@owned argument. bail as this release may well be the final release of
an @owned argument, but somehow rc-identity fails to prove that.

3. A release that is mapped to an argument, but we already has a release
that (partially or completely) overlaps with this release. This release
for sure is not the final release.