bug#34023: Support double colons in Info index entries

[Gavin Smith]

On Thu, Jan 10, 2019 at 07:53:52PM -0500, Glenn Morris wrote:
> Gavin Smith wrote:
> 
> > This is what is implemented in the standalone info browser (since
> > change on 2017-04-08).
> 
> "Defining the Entries of an Index" in the Texinfo manual continues to
> say (through Texinfo 6.5.90) "Caution: Do not use a colon in an index entry".

Even if Info mode and the standalone Info browser are changed to 
support colons in index entries, people running older versions of these 
won't be able to read them.  However, texi2any does output the colon in 
the index entry without complaint.  See attached Texinfo input and Info 
output.  Newer versions of 'info' can deal with the colons in the index 
entries that are output here.

colon-index.info
Description: Text document

colon-index.texi
Description: TeXInfo document