crosutil: automatically strip CFI when uploading x86 symbols
crosutil: automatically strip CFI when uploading x86 symbols

BUG=chromium-os:21030 chromium-os:21417
TEST=test uploads with ARM and x86 targets
test that Chrome symbols are ~87M when stripped down from ~160MB

Change-Id: I9207b3f6a5b757ffa58468c58b4440467dc44738
Reviewed-on: http://gerrit.chromium.org/gerrit/8777
Reviewed-by: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>
Reviewed-by: Michael Krebs <d6638659c20694b0807ba6fa35ee0bac2e482e0f@chromium.org>
Reviewed-by: Ken Mixter <feb6aa3e7f1e44c9811411c1ed2accffd28a2d10@chromium.org>
Tested-by: Ken Mixter <feb6aa3e7f1e44c9811411c1ed2accffd28a2d10@chromium.org>
Commit-Ready: Ken Mixter <feb6aa3e7f1e44c9811411c1ed2accffd28a2d10@chromium.org>

trnubo/scripts,marineam/coreos-scripts,mjg59/scripts,BugRoger/scripts,endocode/scripts,crawford/scripts,trnubo/scripts,nicescale/scripts,mischief/scripts,sigma/coreos-scripts,coreos/scripts,endocode/scripts,bcwaldon/coreos-scripts,glevand/coreos--scripts,andrejro/coreos--scripts,bcwaldon/coreos-scripts,gtank/scripts,coreos/scripts,marineam/coreos-scripts,fivethreeo/scripts,crawford/scripts,smilart/scripts,BugRoger/scripts,vmware/coreos-scripts,mjg59/scripts,vmware/coreos-scripts,vmware/coreos-scripts,crawford/scripts,fivethreeo/scripts,smilart/scripts,gtank/scripts,marineam/coreos-scripts,trnubo/scripts,glevand/coreos--scripts,mischief/scripts,zhang0137/scripts,nicescale/scripts,zhang0137/scripts,mischief/scripts,BugRoger/scripts,andrejro/coreos--scripts,smilart/scripts,bcwaldon/coreos-scripts,endocode/scripts,zhang0137/scripts,sigma/coreos-scripts,mjg59/scripts,andrejro/coreos--scripts,gtank/scripts,nicescale/scripts,sigma/coreos-scripts,fivethreeo/scripts