On Windows, avoid casting a value larger than 2^31 to a (SIZE_T) on systems where it is a 32-bit type.

FossilOrigin-Name: f08d63b413601b22726e8b96ff8eb779857321b9df30db0333f71e50ffb5077d

src/os_unix.c

@@ -3860,7 +3860,8 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
       }
 
       /* The value of newLimit may be eventually cast to (size_t) and passed
-      ** to mmap(). Restrict its value to 2GB if (size_t) is a 32-bit type. */
+      ** to mmap(). Restrict its value to 2GB if (size_t) is not at least a
+      ** 64-bit type. */
       if( newLimit>0 && sizeof(size_t)<8 ){
         newLimit = (newLimit & 0x7FFFFFFF);
       }