Extend nettle_block16 with uint64_t field.

ChangeLog

@@ -9,6 +9,8 @@
 
 2018-01-08  Niels Möller  <nisse@lysator.liu.se>
 
+	* nettle-types.h (union nettle_block16): Add uint64_t field.
+
 	* configure.ac: Check for __builtin_bswap64, define
 	HAVE_BUILTIN_BSWAP64 if available.
 

nettle-types.h

@@ -48,6 +48,7 @@ union nettle_block16
 {
   uint8_t b[16];
   unsigned long w[16 / sizeof(unsigned long)];
+  uint64_t u64[2];
 };
 
 /* Randomness. Used by key generation and dsa signature creation. */