test: test append with two different named types with same element type
test: test append with two different named types with same element type

R=golang-dev, gri
CC=golang-dev
http://codereview.appspot.com/5615045
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go