[release-branch.go1.4] cmd/pprof: fix symbol resolution for remote profiles

««« CL 183080043 / b663cc7e6c15
cmd/pprof: fix symbol resolution for remote profiles

Fixes issue 9199.

LGTM=iant
R=golang-codereviews, iant
CC=austin, golang-codereviews, minux
https://codereview.appspot.com/183080043
»»»

TBR=iant
CC=golang-codereviews
https://codereview.appspot.com/176680043