d2i_ASN1_OBJECT had a similar set of bugs in as in
https://boringssl-review.googlesource.com/c/boringssl/+/49866.
This does not affect any other d2i functions. Those already go through
the ASN1_ITEM machinery.
Update-Note: d2i_ASN1_OBJECT will now notice more incorrect tags. It was
already checking for tag number 6, so it is unlikely anyone was relying
on this as a non-tag-checking parser.
Change-Id: I30f9ad28e3859aeb7a38c0ea299cd2e30002abce
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/50290
Reviewed-by: Adam Langley <agl@google.com>