RFR: Reset coalesce and fill boundary during global collect

[Kelvin Nilsen]

On Thu, 14 Oct 2021 22:27:49 GMT, William Kemper <wkemper at openjdk.org> wrote:

> Normally, this happens during cset selection for the old generation. It also needs to happen for coalesce and fill at the end of global collections or objects may not be filled.

Better service names might be:
  s/reset_coalesce_and_fill_boundary/begin_preemptible_coalesce_and_fill/
  s/finish_coalesce_and_fill/end_preemptible_coalesce_and_fill/
  remove coalesce_and_fill_is_done() <--- this was apparently an incomplete thought of mine

-------------

PR: https://git.openjdk.java.net/shenandoah/pull/90