Add some explicit casts as needed to make ed25519_ref10 compile

Apparently, ref10 likes implicit conversions from int64 to int32 more
than our warnings do.

src/ext/ed25519/ref10/fe_frombytes.c

@@ -60,14 +60,14 @@ void fe_frombytes(fe h,const unsigned char *s)
   carry6 = (h6 + (crypto_int64) (1<<25)) >> 26; h7 += carry6; h6 -= carry6 << 26;
   carry8 = (h8 + (crypto_int64) (1<<25)) >> 26; h9 += carry8; h8 -= carry8 << 26;
 
-  h[0] = h0;
-  h[1] = h1;
-  h[2] = h2;
-  h[3] = h3;
-  h[4] = h4;
-  h[5] = h5;
-  h[6] = h6;
-  h[7] = h7;
-  h[8] = h8;
-  h[9] = h9;
+  h[0] = (crypto_int32) h0;
+  h[1] = (crypto_int32) h1;
+  h[2] = (crypto_int32) h2;
+  h[3] = (crypto_int32) h3;
+  h[4] = (crypto_int32) h4;
+  h[5] = (crypto_int32) h5;
+  h[6] = (crypto_int32) h6;
+  h[7] = (crypto_int32) h7;
+  h[8] = (crypto_int32) h8;
+  h[9] = (crypto_int32) h9;
 }

src/ext/ed25519/ref10/fe_mul.c

@@ -240,14 +240,14 @@ void fe_mul(fe h,const fe f,const fe g)
   /* |h0| <= 2^25; from now on fits into int32 unchanged */
   /* |h1| <= 1.01*2^24 */
 
-  h[0] = h0;
-  h[1] = h1;
-  h[2] = h2;
-  h[3] = h3;
-  h[4] = h4;
-  h[5] = h5;
-  h[6] = h6;
-  h[7] = h7;
-  h[8] = h8;
-  h[9] = h9;
+  h[0] = (crypto_int32) h0;
+  h[1] = (crypto_int32) h1;
+  h[2] = (crypto_int32) h2;
+  h[3] = (crypto_int32) h3;
+  h[4] = (crypto_int32) h4;
+  h[5] = (crypto_int32) h5;
+  h[6] = (crypto_int32) h6;
+  h[7] = (crypto_int32) h7;
+  h[8] = (crypto_int32) h8;
+  h[9] = (crypto_int32) h9;
 }

src/ext/ed25519/ref10/fe_sq.c

@@ -136,14 +136,14 @@ void fe_sq(fe h,const fe f)
 
   carry0 = (h0 + (crypto_int64) (1<<25)) >> 26; h1 += carry0; h0 -= carry0 << 26;
 
-  h[0] = h0;
-  h[1] = h1;
-  h[2] = h2;
-  h[3] = h3;
-  h[4] = h4;
-  h[5] = h5;
-  h[6] = h6;
-  h[7] = h7;
-  h[8] = h8;
-  h[9] = h9;
+  h[0] = (crypto_int32) h0;
+  h[1] = (crypto_int32) h1;
+  h[2] = (crypto_int32) h2;
+  h[3] = (crypto_int32) h3;
+  h[4] = (crypto_int32) h4;
+  h[5] = (crypto_int32) h5;
+  h[6] = (crypto_int32) h6;
+  h[7] = (crypto_int32) h7;
+  h[8] = (crypto_int32) h8;
+  h[9] = (crypto_int32) h9;
 }

src/ext/ed25519/ref10/fe_sq2.c

@@ -147,14 +147,14 @@ void fe_sq2(fe h,const fe f)
 
   carry0 = (h0 + (crypto_int64) (1<<25)) >> 26; h1 += carry0; h0 -= carry0 << 26;
 
-  h[0] = h0;
-  h[1] = h1;
-  h[2] = h2;
-  h[3] = h3;
-  h[4] = h4;
-  h[5] = h5;
-  h[6] = h6;
-  h[7] = h7;
-  h[8] = h8;
-  h[9] = h9;
+  h[0] = (crypto_int32) h0;
+  h[1] = (crypto_int32) h1;
+  h[2] = (crypto_int32) h2;
+  h[3] = (crypto_int32) h3;
+  h[4] = (crypto_int32) h4;
+  h[5] = (crypto_int32) h5;
+  h[6] = (crypto_int32) h6;
+  h[7] = (crypto_int32) h7;
+  h[8] = (crypto_int32) h8;
+  h[9] = (crypto_int32) h9;
 }