8219196: DataOutputStream.writeUTF may throw unexpected exceptions

[Brian Burkhalter]

> On Mar 18, 2019, at 1:03 PM, Martin Buchholz <martinrb at google.com> wrote:
> 
> You've again caught me only half paying attention.
> Below is another attempt at micro-optimization (might be too tricky!), BUT:

This has blossomed considerably from my original effectively one line change. ;-)

Might there be any performance numbers on this version versus the one currently in the repo?

> - consider documenting the UTFDataFormatException and the 64k length limit
> - error message would actually be more useful if it contained a few chars
> from head and tail instead of length

Good ideas.