Clang 14+ introduced a warning when using mixed packed and unpacked structs.
This can cause problems when taking an address of the unpacked struct, which
may end up having a different alignment than expected.
This is not a problem in cgo, which does not take pointers from the packed
struct.
Updated version of https://go.dev/cl/526915, which includes
"-Wunknown-warning-option" for compilers that do not have the specific flag.
Fixes #62480
Change-Id: I788c6604d0ed5267949f4367f148fa26d2116f51
Reviewed-on: https://go-review.googlesource.com/c/go/+/528935
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Carlos Amedee <carlos@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>