compiler warnings in blake2s.c

[wjssz]

If defined __SSE4_1__, and compile with MSVC, there are some data cast warnings.
Patch to fix (this patch is for Python 3.10's bundled blake2 code):

 Modules/_blake2/impl/blake2s.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/Modules/_blake2/impl/blake2s.c b/Modules/_blake2/impl/blake2s.c
index 47514685b8f..781588ea26d 100644
--- a/Modules/_blake2/impl/blake2s.c
+++ b/Modules/_blake2/impl/blake2s.c
@@ -214,7 +214,7 @@ int blake2s_init( blake2s_state *S, size_t outlen )
 
   const blake2s_param P =
   {
-    outlen,
+    ( uint8_t ) outlen,
     0,
     1,
     1,
@@ -237,8 +237,8 @@ int blake2s_init_key( blake2s_state *S, size_t outlen, const void *key, size_t k
 
   const blake2s_param P =
   {
-    outlen,
-    keylen,
+    ( uint8_t ) outlen,
+    ( uint8_t ) keylen,
     1,
     1,
     0,
@@ -325,8 +325,8 @@ int blake2s_update( blake2s_state *S, const uint8_t *in, size_t inlen )
 {
   while( inlen > 0 )
   {
-    size_t left = S->buflen;
-    size_t fill = 2 * BLAKE2S_BLOCKBYTES - left;
+    uint32_t left = S->buflen;
+    uint32_t fill = 2 * BLAKE2S_BLOCKBYTES - left;
 
     if( inlen > fill )
     {
@@ -342,7 +342,7 @@ int blake2s_update( blake2s_state *S, const uint8_t *in, size_t inlen )
     else /* inlen <= fill */
     {
       memcpy( S->buf + left, in, inlen );
-      S->buflen += inlen; // Be lazy, do not compress
+      S->buflen += ( uint32_t ) inlen; // Be lazy, do not compress
       in += inlen;
       inlen -= inlen;
     }