Cast for VC++ compiler errors

sql/log_event.cc:
  Cast for VC++ compiler error
sql/opt_range.cc:
  Cast for VC++ compiler error

sql/log_event.cc

@@ -2638,7 +2638,7 @@ Create_file_log_event::Create_file_log_event(const char* buf, int len,
     We must make copy of 'buf' as this event may have to live over a
     rotate log entry when used in mysqlbinlog
   */
-  if (!(event_buf= my_memdup(buf, len, MYF(MY_WME))) ||
+  if (!(event_buf= my_memdup((byte*)buf, len, MYF(MY_WME))) ||
       (copy_log_event(event_buf, len, old_format)))
     DBUG_VOID_RETURN;
 

sql/opt_range.cc

@@ -2560,8 +2560,8 @@ QUICK_SELECT *get_quick_select_for_ref(THD *thd, TABLE *table, TABLE_REF *ref)
     QUICK_RANGE *null_range;
 
     *ref->null_ref_key= 1;		// Set null byte then create a range
-    if (!(null_range= new QUICK_RANGE(ref->key_buff, ref->key_length,
-				      ref->key_buff, ref->key_length,
+    if (!(null_range= new QUICK_RANGE((char*)ref->key_buff, ref->key_length,
+				      (char*)ref->key_buff, ref->key_length,
 				      EQ_RANGE)))
       goto err;
     *ref->null_ref_key= 0;		// Clear null byte