Android's attestion format uses some ludicrously large tag numbers:
https://developer.android.com/training/articles/security-key-attestation.html#certificate_schema

Add support for these in CBS/CBB. The public API does not change for
callers who were using the CBS_ASN1_* constants, but it is no longer the
case that tag representations match their DER encodings for small tag
numbers.

Chromium needs https://chromium-review.googlesource.com/#/c/chromium/src/+/783254,
but otherwise I don't expect this to break things.

Bug: 214
Change-Id: I9b5dc27ae3ea020e9edaabec4d665fd73da7d31e
Reviewed-on: https://boringssl-review.googlesource.com/23304
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>