RFR: 8315875: GenShen: Remove heap mode check from ShenandoahInitLogger [v2]

[William Kemper]

> There are some additional improvements to the init logger that should be easy to upstream.

William Kemper has updated the pull request incrementally with one additional commit since the last revision:

  Hide global generation behind heap

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

Changes:
  - all: https://git.openjdk.org/shenandoah/pull/320/files
  - new: https://git.openjdk.org/shenandoah/pull/320/files/9ef0a6d6..9960fe7d

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=shenandoah&pr=320&range=01
 - incr: https://webrevs.openjdk.org/?repo=shenandoah&pr=320&range=00-01

  Stats: 6 lines in 3 files changed: 4 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/shenandoah/pull/320.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah.git pull/320/head:pull/320

PR: https://git.openjdk.org/shenandoah/pull/320