makeinfo version check

[Greg Schafer]

Joseph S. Myers wrote:

> GCC has its own makeinfo version check in gcc/configure.ac that may need 
> updating as well, as well as the toplevel one.

Yes, it definitely needs to be similarly updated. It currently looks like
this and fails for texinfo-4.11:


# See if makeinfo has been installed and is modern enough
# that we can use it.
ACX_CHECK_PROG_VER(MAKEINFO, makeinfo, --version,
  [GNU texinfo.* \([0-9][0-9.]*\)],
  [4.[4-9]*])
if test $gcc_cv_prog_makeinfo_modern = no; then
  AC_MSG_WARN([
*** Makeinfo is missing or too old.
*** Info documentation will not be built.])
  BUILD_INFO=
else
  BUILD_INFO=info
fi
AC_SUBST(BUILD_INFO)


Regards
Greg