cmd/go: show comparable in go doc interface output
The go doc command now displays the comparable constraint when embedded
in an interface, matching the existing behavior for the error type.
Previously, when an interface embedded comparable, it was not shown in
the documentation and incorrectly triggered the "Has unexported methods"
message even when no unexported methods existed.
Fixes #76125
Change-Id: Idaae07fcb1dfc79b1fae374f9fc68df0052ff38e
Reviewed-on: https://go-review.googlesource.com/c/go/+/727100 Reviewed-by: Sean Liao <sean@liao.dev> Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Michael Matloob <matloob@google.com> Reviewed-by: Michael Matloob <matloob@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>