bug#21433: 24.5; info viewer and @multitable

[Juri Linkov]

> Multitable appears to break representation of headings in the emacs
> info viewer, drawing them as is instead of using another font. Here is
> a texinfo example:
>
> ----test.texi----
> @node Top
> @top Test
> @chapter Heading-1
> @multitable @columnfractions .2 .4 .2
> @headitem Type @tab Field @tab Example
> @end multitable
> @chapter Heading-2
> test
> -------eof-------
>
> To reproduce:
>
> makeinfo test.texi && emacs -Q --eval '(info "./test.info")'
>
> Removing @headitem or replacing it with @item helps, but then there is
> no headitem. Same happens with @section and @subsection instead of
> @chapter.
>
> GNU texinfo 6.0.

Thanks for the detailed bug report.  Fixed now.