RFR: 8270842: G1: Only young regions need to redirty outside references in remset. [v2]

[Hamlin Li]

> For evac failure objects in non-young regions (old) of cset, the outside reference remset already recorded in the dirty queue, we only needs to do it for obj in young regions

Hamlin Li has updated the pull request incrementally with one additional commit since the last revision:

  replace out-of-date comments

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/4853/files
  - new: https://git.openjdk.java.net/jdk/pull/4853/files/7790e440..88ce3d42

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=4853&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=4853&range=00-01

  Stats: 12 lines in 1 file changed: 0 ins; 7 del; 5 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4853.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4853/head:pull/4853

PR: https://git.openjdk.java.net/jdk/pull/4853