RFR: 8272093: Extract evacuation failure injection from G1CollectedHeap [v2]

[Thomas Schatzl]

> Hi all,
> 
>   can I have reviews for this change that extracts out the evacuation failure injection mechanism from `G1CollectedHeap` into its own class?
> This reduces the amount of code in `G1CollectedHeap` a bit, moving somewhat uninteresting but somewhat important (testing) code out from there. Also documented it a bit. The other reason was that imho it stuck out a bit due to the ifdef's in `G1CollectedHeap`.
> 
> I checked that gcc does compile out the call to `evacuation_should_fail()` in `G1ParScanThreadState` in product mode.
> 
> Testing: tier1, local testing
> 
> Thanks,
>   Thomas

Thomas Schatzl has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains four commits:

 - Merge branch 'master' into 8272093-extract-evac-failure-injector
 - Also remove injector members from product builds
 - Fix initialization order issue with injector
 - Extract evac failure injector from G1CollectedHeap

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

Changes: https://git.openjdk.java.net/jdk/pull/5047/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5047&range=01
  Stats: 330 lines in 7 files changed: 214 ins; 110 del; 6 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5047.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5047/head:pull/5047

PR: https://git.openjdk.java.net/jdk/pull/5047