RFR: 8247908: Replace IsRegisteredEnum with std::is_enum

[David Holmes]

Looks good!

Thanks Kim!

David
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On 23/07/2020 5:27 pm, Kim Barrett wrote:
> Please review this change which removes our IsRegisteredEnum type
> trait and its uses, instead using the std::is_enum<> type trait.
> 
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8247908
> 
> Webrev:
> https://cr.openjdk.java.net/~kbarrett/8247908/open.00/
> 
> Testing:
> mach5 tier1
>