Fix exit locations dump (#6703)

While I was working on my RubyConf talk for tracing yjit exit locations
I realized that there were exits from the dump code included in the
stats data. For example I saw 224 interp leave exits for a simple script
that should have had 1 or 2. I realized that the dump code needs to be
called _after_ the stats are generated, otherwise the dump code will be
counted in the stats exits.

I've added a `_dump_locations` method to the `at_exit` for stats
generation to ensure that it runs last. I've updated the documentation
to add a note that if you call `dump_exit_locations` directly, your
stats will include the dump code exits as well.

0 files changed, 0 insertions, 0 deletions