CL 233857 fixed the underlying issue for #37246,
which had arisen again as #38916.
Add the test case from #37246 to ensure it stays fixed.
Fixes#37246
Change-Id: If7fd75a096d2ce4364dc15509253c3882838161d
Reviewed-on: https://go-review.googlesource.com/c/go/+/233941
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <mike.munday@ibm.com>
