Review request for JMC-6468: Rule for detecting unsupported JDK version

[Guru]

+1 for http://cr.openjdk.java.net/~hirt/JMC-6468/webrev.3/ <http://cr.openjdk.java.net/~hirt/JMC-6468/webrev.3/> 

Tested with OpenJDK {9.0.1, 10.0.1, 11.0.0} and also with JDK 8.

Thanks,
Guru
> On 15-May-2019, at 2:58 AM, Marcus Hirt <marcus at hirt.se> wrote:
> 
> Hi all,
> 
> Please review this enhancement for warning when an unsupported JDK version 
> is being used (such as when an old non-LTS release is in use, or a very 
> old no longer supported version, or an early access release).
> 
> There are various ways this could be done, but the rule will currently 
> be fine with actively supported releases (JDK 8, JDK 11), or the latest 
> non-LTS release (currently JDK 12). It will be a little bit grumpy about 
> JDK 7 (still supported by some vendors), and decidedly unhappy about 
> earlier releases and non-LTS releases not being the latest.
> 
> Note that given the update cycle of this rule, and the multitude of vendors
> releasing and supporting OpenJDK based JVMs, this rule does not attempt to 
> discover if an old interim/update of a supported release is in use. It is 
> only complaining about the feature release in use.
> 
> See also: http://openjdk.java.net/jeps/322
> 
> Jira:   https://bugs.openjdk.java.net/browse/JMC-6468
> Webrev: http://cr.openjdk.java.net/~hirt/JMC-6468/webrev.2/
> 
> Kind regards,
> Marcus
>