internal/reflectlite: include Kind in ValueError message

The implementation has been ported from reflect, but to avoid
introducing a dependency on strconv, Kind.String() falls back to
"invalid" if the Kind is unknown rather than "kind" + strconv.Itoa(int(k))

Fixes #39286

Change-Id: I82277242a6c41d0146dabd9d20339fe72d562500
Reviewed-on: https://go-review.googlesource.com/c/go/+/235522


Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Trust: Dmitri Shuralyov <dmitshur@golang.org>