There wasn't one. I was mucking around with the Sendfile internals in
CL 154663 so I need one to make sure I didn't break anything.
Change-Id: I38b25de4995831680fdac440dfa7f26542d2624f
Reviewed-on: https://go-review.googlesource.com/c/154664
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
