runtime: remove unused goc2c.c         Its functionality has been moved into cmd/dist.
runtime: remove unused goc2c.c
        Its functionality has been moved into cmd/dist.

R=golang-dev, r, iant
CC=golang-dev
http://codereview.appspot.com/5843062

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