Proposal: Replace foreach loop with Iterable.forEach in String.join(CharSequence, Iterable)

[Donald Raab]

The following code:

for (CharSequence cs: elements) {
    joiner.add(cs);
}

Can be replaced with:

elements.forEach(joiner::add);

This would have the minor benefit of making it safe to use String.join with 
synchronized collections without requiring a client side lock. There are likely 
other opportunities like this in the JDK. 

Also, with the addition of forEach on Iterable, and Predicate in Java 8, the 
following design FAQ is outdated.

https://docs.oracle.com/en/java/javase/16/docs/api/java.base/java/util/doc-files/coll-designfaq.html#a6
 
<https://docs.oracle.com/en/java/javase/16/docs/api/java.base/java/util/doc-files/coll-designfaq.html#a6>
 

Thanks,
Don