install_toolchain: add dev-lang/go to package.provided on board sysroots.

All Go ebuilds (dev-go/*) depend on dev-lang/go. For cross compiling,
the dependency is satisfied by cross-${CTARGET}/go crossdev packages.
emerge-${BOARD} should not try to install dev-lang/go on the board.

BUG=chromium:372937
TEST=`setup_board --board=panther` correctly adds dev-lang/go to
/build/panther/etc/portage/profile/package.provided

Change-Id: I554b0d190dd11ca4164413406259a483f1953d1c
Reviewed-on: https://chromium-review.googlesource.com/291067
Commit-Ready: Rahul Chaudhry <rahulchaudhry@chromium.org>
Tested-by: Rahul Chaudhry <rahulchaudhry@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed