CONTRIBUTORS: add Damien Neil

LGTM=r
R=r
CC=golang-codereviews
https://codereview.appspot.com/159920044

Committer: Rob Pike <r@golang.org>
reflect: fix struct size calculation to include terminal padding

LGTM=r
R=r
CC=golang-codereviews
https://codereview.appspot.com/160920045

Committer: Rob Pike <r@golang.org>