RFR: Bootstrap old gc should honor aging cycle

[Kelvin Nilsen]

A bootstrap old gc should increment object and region ages if this is an aging cycle.  This patch implements this fix.

The patch is motivated by observations that performance degradation occurs when timely promotions do not occur because bootstrap old GCs are not incrementing ages.

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

Commit messages:
 - Merge remote-tracking branch 'GitFarmBranch/bootstrap-old-gc-should-honor-aging-cycle' into bootstrap-old-gc-should-honor-aging-cycle
 - Bootstrap and OLD GC should age OLD objects

Changes: https://git.openjdk.org/shenandoah/pull/215/files
 Webrev: https://webrevs.openjdk.org/?repo=shenandoah&pr=215&range=00
  Stats: 6 lines in 1 file changed: 5 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/shenandoah/pull/215.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah pull/215/head:pull/215

PR: https://git.openjdk.org/shenandoah/pull/215