Proposal: Use backports for release stabilization

[Mark Reinhold]

2023/5/22 16:25:15 -0400, mark.reinhold at oracle.com:
> Last month, Erik Duveblad proposed that we change the way in which we
> stabilize releases [1].
> 
> To summarize: Currently, to fix a bug in the release being stabilized
> you create a pull request against the stabilization repository (e.g.,
> jdk21).  Jesper periodically merges changes from the stabilization
> repository to the main-line repository (jdk), but if the merge contains
> commits that were intended only for the stabilization repository then
> they have to be backed out -- which sometimes doesn’t happen.
> 
> Erik proposes that we instead use the Skara backport mechanism, which
> we already use for update releases.  To fix a bug in the release being
> stabilized you’d first create a PR against the main-line repository.
> Then, after that PR is reviewed and integrated, you’d use Skara’s
> `/backport` command to backport the fix to the stabilization repository.
> If your fix is intended only for the stabilization repository then you’d
> create a PR directly against that repository.
> 
> Please see Erik’s proposal [1] for further details.
> 
> In my view this is a good proposal, and I thank Erik for writing it up.
> We’ve already had some discussion of it, and Erik and Kevin addressed
> the concerns raised.  Further feedback from JDK Project Committers and
> Reviewers [2] is welcome, as are reasoned objections.  If no such
> objections are raised by 23:59 UTC on Monday, 29 May, or if they’re
> raised and then satisfactorily answered, then we’ll adopt this process
> for JDK 21 and also update JEP 3 [3] and the Developers’ Guide [4]
> accordingly.
> 
> 
> [1] https://mail.openjdk.org/pipermail/jdk-dev/2023-April/007612.html
> [2] https://openjdk.org/census#jdk
> [3] https://openjdk.org/jeps/3
> [4] https://openjdk.org/guide/

Hearing no objections, we will adopt this process as of JDK 21.

- Mark