cmd/go: include coverage build flags for "go list"

cmd/go: include coverage build flags for "go list"

This patch ensures that the go command's "list" subcommand accepts
coverage-related build options, which were incorrectly left out when
"go build -cover" was rolled out. This is needed in order to do things
like check the staleness of an installed cover-instrumented target.

Fixes #57785.

Change-Id: I140732ff1e6b83cd9c453701bb8199b333fc0f2e
Reviewed-on: https://go-review.googlesource.com/c/go/+/462116
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>