spec: rewrite the description of panic and recover. The old description was misleading and inaccurate.
spec: rewrite the description of panic and recover.
The old description was misleading and inaccurate.

Fixes issue 4774.

R=iant, rsc, gri
CC=golang-dev
https://codereview.appspot.com/7761044

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