cmd/go: add telemetry counters for flag names and subcommand
For #58894,#65586
This is a revert of CL 560655 which was a revert of CL 559519.
CL 559519 was reverted because it was broken on windows/386. But now
CL 562715 pulls in x/telemetry CL 560462 which disables telemetry on
windows/386, fixing that issue.
Change-Id: I094e90c28bca02f2303807d3b008f2ef9d59433c
Reviewed-on: https://go-review.googlesource.com/c/go/+/562735 Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Michael Matloob <matloob@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>