internal/coverage: refactor EmitPercent in preparation for bugfix
Refactor cformat.EmitPercent to accept a package filter (list of
packages to report). This is a no-op in terms of exposed coverage
functionality, but we will need this feature in a subsequent patch.
Updates #65570.
Change-Id: I04ddc624a634837ea31c12ec395aa1295a0ea1f1
Reviewed-on: https://go-review.googlesource.com/c/go/+/592204
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: David Chase <drchase@google.com>