[PATCH] Docs: Prevent build failures when "makeinfo" is missing

[Nick Clifton]

Hi Vlad, Hi Cupertino,

> The patch is not OK considering that it is changing generated files.

Plus if the user really does want to generate the info files, but they
do not have makeinfo installed, then "make info" is going to fail to
build them but still claim success.

> Nevertheless, it appears that binutils has a hard requirement on makeinfo.
> When used without makeinfo, it prints this message:
> 
> WARNING: 'makeinfo' is missing on your system.

It is more of a hard/soft requirement.  The problem is timestamps.  

If the timestamps on the *.info files in the sources are newer than
the corresponding *.texi/*.texinfo files then makeinfo is not needed.
Most of the time this will be the case.  But, if you have a new set of
sources, say because you have just downloaded a source tarball, or checked
out a branch from the repository, then the timestamps of the info and texi 
files are likely to be the same.  This will cause the makefile to decide
that the info files need to be regenerated and hence makeinfo will be 
needed.  This happens even if the info files are in fact up to date and
do not need regenerating.

Cheers
  Nick