The original go tool pprof (written in Perl) got this right.
The Go rewrite never has, but should.

Change-Id: Ie1fc571214c61b1b5654a0bc90e15eb889adf059
Reviewed-on: https://go-review.googlesource.com/32617
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>