Moved mpi_inv_mod() outside POLARSSL_GENPRIME
(cherry picked from commit d9374b05d67ca1abcfe0f6b289b6583b6257eee3)

Conflicts:
	ChangeLog
diff --git a/library/bignum.c b/library/bignum.c
index 5087308..052cc25 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -1627,8 +1627,6 @@
     return( ret );
 }
 
-#if defined(POLARSSL_GENPRIME)
-
 /*
  * Modular inverse: X = A^-1 mod N  (HAC 14.61 / 14.64)
  */
@@ -1724,6 +1722,8 @@
     return( ret );
 }
 
+#if defined(POLARSSL_GENPRIME)
+
 static const int small_prime[] =
 {
         3,    5,    7,   11,   13,   17,   19,   23,