RFR(s): 8060192: Add default method Collection.toArray(generator)

[Stuart Marks]

Hi all,

Please review this small enhancement to add a default method 
Collection.toArray(generator) that takes a function that creates the destination 
array. This is analogous to Stream.toArray(generator).

Bug:

     https://bugs.openjdk.java.net/browse/JDK-8060192

Webrev:

     http://cr.openjdk.java.net/~smarks/reviews/8060192/webrev.0/

Thanks,

s'marks