Add #defines for ASN.1 NULL and GENERALIZEDTIME.

Change-Id: Ic82ab5de4e231cdf6230ee7262c3c7539404d4a6
Reviewed-on: https://boringssl-review.googlesource.com/5020
Reviewed-by: David Benjamin <davidben@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/include/openssl/bytestring.h b/include/openssl/bytestring.h
index 9963426..6f6af7c 100644
--- a/include/openssl/bytestring.h
+++ b/include/openssl/bytestring.h
@@ -121,10 +121,12 @@
 #define CBS_ASN1_INTEGER 0x2
 #define CBS_ASN1_BITSTRING 0x3
 #define CBS_ASN1_OCTETSTRING 0x4
+#define CBS_ASN1_NULL 0x5
 #define CBS_ASN1_OBJECT 0x6
 #define CBS_ASN1_ENUMERATED 0xa
 #define CBS_ASN1_SEQUENCE (0x10 | CBS_ASN1_CONSTRUCTED)
 #define CBS_ASN1_SET (0x11 | CBS_ASN1_CONSTRUCTED)
+#define CBS_ASN1_GENERALIZEDTIME 0x18
 
 #define CBS_ASN1_CONSTRUCTED 0x20
 #define CBS_ASN1_CONTEXT_SPECIFIC 0x80