When building a package, run the cover tool on the collected go/cgo
source files before invoking swig (if swig files are present), as
opposed to running swig and then cover. Running swig adds new Go files
to the "cgo" list, and we want to avoid running those newly generated
files through the cover tool.
Fixes #64661.
Cq-Include-Trybots: luci.golang.try:gotip-linux-amd64-longtest
Change-Id: I32b6dad5c39fcf5e656c40fb3b44220c69320889
Reviewed-on: https://go-review.googlesource.com/c/go/+/552095
Auto-Submit: Than McIntosh <thanm@google.com> Reviewed-by: Bryan Mills <bcmills@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>