Tagging proposal for JDK GA releases

[Seán Coffey]

I'd like to propose an enhancement to the JDK build-tagging
convention to help users more easily identify JDK GA releases
via Mercurial tag names.

The concept is quite simple and lets people identify snapshots
of GA releases in Mercurial history without having to know the
build number of the GA release.

For example, to obtain JDK 10.0.2 GA sources today, one issues the
`hg update -r jdk-10.0.2+13` command. With the proposed
enhancement, `hg update -r jdk-10.0.2-ga` could have been used.
It's proposed that the new ga tag would be in addition to the regular
GA build number tag. It would be added to the relevant repository
once the GA milestone has been reached.

This new convention would be used for future JDK releases and is
tracked via JDK-8180946[1]. If the changes are adopted, I can
look at retroactively adding labels for all feature JDK GA releases
since JDK 7 to the JDK feature-release main-line repository.

To accommodate the new tag format, some simple jcheck edits
would be required. Test checks would also be added.

Comments?

regards,
Sean.

[1] https://bugs.openjdk.java.net/browse/JDK-8180946