The original analysis of the Go corpus assumed that these
stripped monotonic time. During the design discussion we
decided to try not stripping monotonic time here, but existing
code works better if we do.

See the discussion on golang.org/issue/18991 for more details.

For #18991.

Change-Id: I04d355ffe56ca0317acdd2ca76cb3033c277f6d1
Reviewed-on: https://go-review.googlesource.com/37542Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>