eclass/go-module.eclass: Upgraded to upstream

Bring in the eclass from portage commit
87ff901f0bac25361c97951c53e7e93e5e75af41.

This is needed to properly set the GOARCH environment variable so that
we can compile node_exporter for the proper architecture like arm or
arm64. That happens with `go-env_set_compile_environment`.

BUG=b:314683192
TEST=emerge-trogdor app-metrics/node_exporter
     file build/trogdor/usr/sbin/node_exporter | grep aarch64

Change-Id: I33546d872413120bfa76858230ad3d98b4db0580
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/5378063
Commit-Queue: Stephen Boyd <swboyd@chromium.org>
Tested-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
2 files changed