Merge bitcoin#877: Add missing secp256k1_ge_set_gej_var decl.

482e4a9 Add missing secp256k1_ge_set_gej_var decl. (Russell O'Connor)

Pull request description:

ACKs for top commit:
  sipa:
    utACK 482e4a9
  real-or-random:
    utACK bitcoin-core/secp256k1@482e4a9
  jonasnick:
    ACK 482e4a9

Tree-SHA512: 02195390fb79f08bcfd655dc56115ea37df42c1ad8f1123b26e7426e387d9658a3bb18fe9951140fc4dd78ce222b84d8b75ce77aec884675e0c26a2005dd2ddc

src/group.h

@@ -62,9 +62,12 @@ static int secp256k1_ge_is_valid_var(const secp256k1_ge *a);
 /** Set r equal to the inverse of a (i.e., mirrored around the X axis) */
 static void secp256k1_ge_neg(secp256k1_ge *r, const secp256k1_ge *a);
 
-/** Set a group element equal to another which is given in jacobian coordinates */
+/** Set a group element equal to another which is given in jacobian coordinates. Constant time. */
 static void secp256k1_ge_set_gej(secp256k1_ge *r, secp256k1_gej *a);
 
+/** Set a group element equal to another which is given in jacobian coordinates. */
+static void secp256k1_ge_set_gej_var(secp256k1_ge *r, secp256k1_gej *a);
+
 /** Set a batch of group elements equal to the inputs given in jacobian coordinates */
 static void secp256k1_ge_set_all_gej_var(secp256k1_ge *r, const secp256k1_gej *a, size_t len);