RFR 8024405: Spliterators.spliterator should support CONCURRENT characteristic

[Paul Sandoz]

Hi,

http://cr.openjdk.java.net/~psandoz/tl/JDK-8024405-spliterators-size-concurrent/webrev/

This fixes an oversight in creating spliterators from the iterator of a collection or directly from an iterator (+ primitive variants).

If CONCURRENT is supplied as a characteristic then the returned spliterator should not report SIZED/SUBSIZED.

This could have resulted in an issue with ArrayBlockingQueue since it's spliterator is created from a weakly consistently iterator and thus exact size is not known.

A CCC is required.

Paul.