reflect: test to make sure big Zero()-obtained objects are really zero.
reflect: test to make sure big Zero()-obtained objects are really zero.

Update issue 6876.

R=dave, bradfitz
CC=golang-dev
https://codereview.appspot.com/36370043

wesolows/golang,wesolows/golang,firebitsbr/golang-old,firebitsbr/golang-old,firebitsbr/golang-old,firebitsbr/golang-old,wesolows/golang-old,wesolows/golang-old,firebitsbr/golang-old,wesolows/golang,wesolows/golang-old,wesolows/golang,firebitsbr/golang-old,wesolows/golang,wesolows/golang-old,firebitsbr/golang-old,wesolows/golang-old,firebitsbr/golang-old,wesolows/golang,wesolows/golang-old,wesolows/golang-old,wesolows/golang