RFR: JDK-8260208: fix dummy object filling condition in G1CollectedHeap::f…

[Hamlin Li]

it's a minor fix/enhancement in cds, it fixes dummy object filling condition in G1CollectedHeap::fill_archive_regions

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

Commit messages:
 - JDK-8260208: fix dummy object filling condition in G1CollectedHeap::fill_archive_regions in cds

Changes: https://git.openjdk.java.net/jdk/pull/2183/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2183&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8260208
  Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2183.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2183/head:pull/2183

PR: https://git.openjdk.java.net/jdk/pull/2183