Fix ASN1_INTEGER handling.

Only treat an ASN1_ANY type as an integer if it has the V_ASN1_INTEGER
tag: V_ASN1_NEG_INTEGER is an internal only value which is never used
for on the wire encoding.

(Imported from upstream's d4b25980020821d4685752ecb9105c0902109ab5.)

This is redundant with our fb2c6f8c8565e1e2d85c24408050c96521acbcdc which I
think is a much better fix (having two notions of "type" depending on whether
we're in an ASN1_TYPE or an ASN1_STRING is fragile), so I think we should keep
our restriction too. Still, this is also worth doing.

Change-Id: I6ea54aae7b517a59c6e563d8c993d0ee22e25bee
Reviewed-on: https://boringssl-review.googlesource.com/7848
Reviewed-by: Adam Langley <agl@google.com>

crypto/asn1/a_type.c

diff --git a/crypto/asn1/a_type.c b/crypto/asn1/a_type.c
index ecd4734..734ff8b 100644
--- a/crypto/asn1/a_type.c
+++ b/crypto/asn1/a_type.c
@@ -122,9 +122,7 @@
         result = a->value.boolean - b->value.boolean;
         break;
     case V_ASN1_INTEGER:
-    case V_ASN1_NEG_INTEGER:
     case V_ASN1_ENUMERATED:
-    case V_ASN1_NEG_ENUMERATED:
     case V_ASN1_BIT_STRING:
     case V_ASN1_OCTET_STRING:
     case V_ASN1_SEQUENCE:

crypto/asn1/tasn_dec.c

diff --git a/crypto/asn1/tasn_dec.c b/crypto/asn1/tasn_dec.c
index 40d575d..616b587 100644
--- a/crypto/asn1/tasn_dec.c
+++ b/crypto/asn1/tasn_dec.c
@@ -894,9 +894,7 @@
         break;
 
     case V_ASN1_INTEGER:
-    case V_ASN1_NEG_INTEGER:
     case V_ASN1_ENUMERATED:
-    case V_ASN1_NEG_ENUMERATED:
         tint = (ASN1_INTEGER **)pval;
         if (!c2i_ASN1_INTEGER(tint, &cont, len))
             goto err;

crypto/asn1/tasn_enc.c

diff --git a/crypto/asn1/tasn_enc.c b/crypto/asn1/tasn_enc.c
index a56d08e..409d138 100644
--- a/crypto/asn1/tasn_enc.c
+++ b/crypto/asn1/tasn_enc.c
@@ -609,9 +609,7 @@
         break;
 
     case V_ASN1_INTEGER:
-    case V_ASN1_NEG_INTEGER:
     case V_ASN1_ENUMERATED:
-    case V_ASN1_NEG_ENUMERATED:
         /*
          * These are all have the same content format as ASN1_INTEGER
          */