RFR JDK-8215300: additional changes to constants API

[Brian Goetz]

+1 from me.

Appears that it covers all the issues that were raised in the CSR and by JCK since integration.

> On Dec 13, 2018, at 10:14 AM, Vicente Romero <vicente.romero at oracle.com> wrote:
> 
> Hi all,
> 
> I have provided another iteration to the webrev at [1]. This one includes additional changes to make sure that no array descriptor with more than 255 dimensions is created.
> 
> Thanks,
> Vicente
> 
> http://cr.openjdk.java.net/~vromero/8215300/webrev.01/
> 
> 
> On 12/12/18 12:02 PM, Vicente Romero wrote:
>> Hi,
>> 
>> Please review some final changes to the constants API. The changes should make the API clearer and more precise and were recommended in the CSR [3]
>> 
>> Thanks,
>> Vicente
>> 
>> [1] (jira issue) https://bugs.openjdk.java.net/browse/JDK-8215300
>> [2] (webrev) http://cr.openjdk.java.net/~vromero/8215300/webrev.00/
>> [3] https://bugs.openjdk.java.net/browse/JDK-8202031
>