Calling Decoder.Decode on a message which contains deeply nested structures can cause a panic due to stack exhaustion.

This is CVE-2022-30635.

(This was a PRIVATE issue tracked in http://b/231318421 and fixed by http://tg/1484771.)

/cc https://github.com/orgs/golang/teams/security and https://github.com/orgs/golang/teams/release