Making java.util.Iterator.remove() for the iterators for EnumSet more resilient

[Alan Bateman]

Neil Richards wrote:
> Please advise me on what steps remain for this change to be committed.
>   
I think the main thing with this proposal is getting agreement that it 
is the right thing to do. On one hand it avoids the set getting 
corrupted. On the other hand it's masking a problem and really part of a 
bigger issue. This isn't really my area but it kinda feels like we need 
a run mode or some way to enable concurrent modification exceptions so 
that the developer has some chance to fix the real issues.

-Alan.