The SSE4.1 implementation is fine on MSVC/x86, reenable it

src/libsodium/crypto_generichash/blake2/ref/blake2b-compress-sse41.c

@@ -6,7 +6,7 @@
 #include <string.h>
 
 #if (defined(HAVE_EMMINTRIN_H) && defined(HAVE_TMMINTRIN_H) && defined(HAVE_SMMINTRIN_H)) || \
-    (defined(_MSC_VER) && (defined(_M_X64) || defined(_M_AMD64)))
+    (defined(_MSC_VER) && (defined(_M_X64) || defined(_M_AMD64) || defined(_M_IX86)))
 
 #pragma GCC target("sse2")
 #pragma GCC target("ssse3")

src/libsodium/crypto_generichash/blake2/ref/blake2b-ref.c

@@ -406,7 +406,7 @@ int
 blake2b_pick_best_implementation(void)
 {
 #if (defined(HAVE_EMMINTRIN_H) && defined(HAVE_TMMINTRIN_H) && defined(HAVE_SMMINTRIN_H)) || \
-    (defined(_MSC_VER) && (defined(_M_X64) || defined(_M_AMD64)))
+    (defined(_MSC_VER) && (defined(_M_X64) || defined(_M_AMD64) || defined(_M_IX86)))
   if (sodium_runtime_has_sse41()) {
     blake2b_compress = blake2b_compress_sse41;
     return 0;