generating frame information in errors will cause this
function to no longer be inlined.

Updates #29934.

Change-Id: I1d7bc11707f1872d7315f627bfb9a12afa41e358
Reviewed-on: https://go-review.googlesource.com/c/161760


Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>