RFR(S): JDK-8247938: Change various JVM enums like LinkInfo::AccessCheck and Klass::DefaultsLookupMode to enum class

[Kim Barrett]

> On Aug 3, 2020, at 11:12 AM, Lois Foltan <lois.foltan at oracle.com> wrote:
> 
> Thank you Kim for the review!  I do like your suggestion of changing the names of the enumerators.  New webrev to include that renaming as part of this change.
> 
> New webrev at: http://cr.openjdk.java.net/~lfoltan/bug_jdk8247938.1/webrev
> 
> Retesting hs-tier1-3.
> 
> Thanks,
> Lois

Looks good.

BTW, for possible future work, LinkInfo might be a candidate for using
delegating constructors.