crypto/x509: gate Policies marshaling with GODEBUG
Use a GODEBUG to choose which certificate policy field to use. If
x509usepolicies=1 is set, use the Policies field, otherwise use the
PolicyIdentifiers field.
Fixes #64248
Change-Id: I3f0b56102e0bac4ebe800497717c61c58ef3f092
Reviewed-on: https://go-review.googlesource.com/c/go/+/546916 Reviewed-by: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>