ed25519/curve25519: only build SSE2 variants on x86

Signed-off-by: Steven Noonan <[email protected]>

Author: Steven Noonan

src/external/curve25519-donna/curve25519_VALVE_sse2.c

@@ -2,7 +2,11 @@
    where it is explicitly placed in the public domain. This wrapper compiles it with the _sse2
    function suffix to be distinguished from the native C version. */
 
+#if defined( _M_IX86 ) || defined( _M_X64 ) || defined(__SSE2__)
+
 #define CURVE25519_SUFFIX _sse2
 #define CURVE25519_SSE2
 
 #include "curve25519.c"
+
+#endif

src/external/ed25519-donna/ed25519_VALVE_sse2.c

@@ -1,6 +1,6 @@
 /*========= Copyright © Valve Corporation, All rights reserved =======================*/
 
-
+#if defined( _M_IX86 ) || defined( _M_X64 ) || defined(__SSE2__)
 #define ED25519_SSE2
 #define ED25519_SUFFIX _sse2
 
@@ -12,3 +12,4 @@
 #define batch_point_buffer test_batch_point_buffer_sse2
 
 #include "ed25519_VALVE.c"
+#endif