cmd/go: better advice for heap profiling
cmd/go: better advice for heap profiling

R=golang-codereviews, bradfitz
CC=golang-codereviews
https://codereview.appspot.com/60760048

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