In particular bring in CL 201973, which reverts support for multiple
keys in a struct tag.
For #40281
For #43083
For #43226
Change-Id: I66e76639cbbca55bdbff6956acdb0a97650fdd31
Reviewed-on: https://go-review.googlesource.com/c/go/+/282412
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>