Code review request for JDK-8014365 Restore Objects.requireNonNull(T, Supplier<String>)

[Joe Darcy]

Hello,

Please (re)review this change to introduce Objects.requireNonNull(T, 
Supplier<String>):

     http://cr.openjdk.java.net/~darcy/8014365.0/

The original change had to be pulled out because of a build issue 
(8012343: Objects.requireNonNull(Object,Supplier) breaks genstubs 
build); I'll be asking for a review on build-dev of the build-related 
change in langtools. The test portion of the patch is slightly different 
than before because of the intervening changes made for

     8013712: Add Objects.nonNull and Objects.isNull

Thanks,

-Joe