Tag a number of globals as const.

Change-Id: I6f334911f153395a2e5e26adfd08912a1d8c558b
Reviewed-on: https://boringssl-review.googlesource.com/2847
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/include/openssl/asn1.h b/include/openssl/asn1.h
index a9864bc..941b156 100644
--- a/include/openssl/asn1.h
+++ b/include/openssl/asn1.h
@@ -1052,7 +1052,7 @@
 OPENSSL_EXPORT unsigned long ASN1_PCTX_get_str_flags(ASN1_PCTX *p);
 OPENSSL_EXPORT void ASN1_PCTX_set_str_flags(ASN1_PCTX *p, unsigned long flags);
 
-OPENSSL_EXPORT BIO_METHOD *BIO_f_asn1(void);
+OPENSSL_EXPORT const BIO_METHOD *BIO_f_asn1(void);
 
 OPENSSL_EXPORT BIO *BIO_new_NDEF(BIO *out, ASN1_VALUE *val, const ASN1_ITEM *it);
 
diff --git a/include/openssl/x509.h b/include/openssl/x509.h
index 475f747..1ee63a1 100644
--- a/include/openssl/x509.h
+++ b/include/openssl/x509.h
@@ -871,8 +871,8 @@
 OPENSSL_EXPORT int		X509_REQ_set_pubkey(X509_REQ *x, EVP_PKEY *pkey);
 OPENSSL_EXPORT EVP_PKEY *	X509_REQ_get_pubkey(X509_REQ *req);
 OPENSSL_EXPORT int		X509_REQ_extension_nid(int nid);
-OPENSSL_EXPORT int *		X509_REQ_get_extension_nids(void);
-OPENSSL_EXPORT void		X509_REQ_set_extension_nids(int *nids);
+OPENSSL_EXPORT const int *	X509_REQ_get_extension_nids(void);
+OPENSSL_EXPORT void		X509_REQ_set_extension_nids(const int *nids);
 OPENSSL_EXPORT STACK_OF(X509_EXTENSION) *X509_REQ_get_extensions(X509_REQ *req);
 OPENSSL_EXPORT int X509_REQ_add_extensions_nid(X509_REQ *req, STACK_OF(X509_EXTENSION) *exts,
 				int nid);
diff --git a/include/openssl/x509v3.h b/include/openssl/x509v3.h
index 9aa91d6..c891022 100644
--- a/include/openssl/x509v3.h
+++ b/include/openssl/x509v3.h
@@ -130,7 +130,7 @@
 X509 *subject_cert;
 X509_REQ *subject_req;
 X509_CRL *crl;
-X509V3_CONF_METHOD *db_meth;
+const X509V3_CONF_METHOD *db_meth;
 void *db;
 /* Maybe more here */
 };
@@ -389,7 +389,7 @@
 			(X509V3_EXT_I2V)i2v_ASN1_BIT_STRING, \
 			(X509V3_EXT_V2I)v2i_ASN1_BIT_STRING, \
 			NULL, NULL, \
-			table}
+			(void *)table}
 
 #define EXT_IA5STRING(nid) { nid, 0, ASN1_ITEM_ref(ASN1_IA5STRING), \
 			0,0,0,0, \