RFR: 8254167 G1: Record regions where evacuation failed to provide targeted iteration [v8]

[Hamlin Li]

> This is another try to optimize evcuation failure for regions.
> I record evacuation failed regions, and iterate these regions directly rather than iterate the whole cset.
> The implementation reuses and refactors some of the existing data in g1CollectedHeap (_regions_failed_evacuation, _num_regions_failed_evacuation), and records these regions in an array, and iterate this array later in post evacuation phase.
> 
> I have 2 implementations:
> 
> - 1) CHT (Initial version)
> - 2) bitmap (latest version, reuse _regions_failed_evacuation in g1CollectedHeap)
> 
> This implementation does not consider work distribution as mentioned in JDK-8254167 yet. But seems it already get better&stable performance gain than origin. We could improve it further later if work distribution is necessary.
> 
> I will attach the perf data in JBS.

Hamlin Li has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains ten commits:

 - Merge
 - Fix misc issues
 - Refactor par iteration for regions of cset and evac failure.
 - Modify as review comments suggested.
 - merge from master
 - Fix missing header files
 - reuse original bitmap rather than CHT
 - merge with existing classes
 - Initial commit

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Changes: https://git.openjdk.java.net/jdk/pull/5272/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5272&range=07
  Stats: 293 lines in 12 files changed: 229 ins; 38 del; 26 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5272.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5272/head:pull/5272

PR: https://git.openjdk.java.net/jdk/pull/5272