tabs in `@example`

In the info file I read the following about `@example`.

     Caution: Do not use tabs in the lines of an example!  (Or
     anywhere else in Texinfo, except in verbatim environments.)  TeX
     treats tabs as single spaces, and that is not what they look
     like.

However, this is not fully correct.  Consider the following input
file.

```
\input texinfo

@example
no leading space
	leading tab	another tab
        eight leading spaces
@end example

@bye
```

If processed with `texi2pdf`, the leading tab vanishes completely (as
shown in the image); it is not treated as a single space.