Remove the ambiguity, know that we know it's actually broken,
per https://github.com/golang/go/issues/23073#issuecomment-351045421

Updates #23073

Change-Id: I9b904da2f4c7105a0727d2a9056aaa6895d3dadc
Reviewed-on: https://go-review.googlesource.com/83856Reviewed-by: Ian Lance Taylor <iant@golang.org>