Hide strict-aliasing warning with gcc 4.7

Signed-hostap: Jouni Malinen <j@w1.fi>

src/crypto/md5-internal.c

@@ -176,8 +176,8 @@ void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
     byteReverse(ctx->in, 14);
 
     /* Append length in bits and transform */
-    ((u32 *) ctx->in)[14] = ctx->bits[0];
-    ((u32 *) ctx->in)[15] = ctx->bits[1];
+    ((u32 *) aliasing_hide_typecast(ctx->in, u32))[14] = ctx->bits[0];
+    ((u32 *) aliasing_hide_typecast(ctx->in, u32))[15] = ctx->bits[1];
 
     MD5Transform(ctx->buf, (u32 *) ctx->in);
     byteReverse((unsigned char *) ctx->buf, 4);