runtime: plan 9 does have /dev/random
runtime: plan 9 does have /dev/random

R=golang-codereviews, r, aram
CC=0intro, golang-codereviews, rsc
https://codereview.appspot.com/43420045

Committer: Rob Pike <4dc7c9ec434ed06502767136789763ec11d2c4b7@golang.org>

pombredanne/go-deleteme,tv42/old-go,pombredanne/go-deleteme,tv42/old-go,pombredanne/go-deleteme,pombredanne/go-deleteme,tv42/old-go,pombredanne/go-deleteme,pombredanne/go-deleteme,tv42/old-go,pombredanne/go-deleteme,tv42/old-go,tv42/old-go,tv42/old-go