4.5: @set before @setfilename is ignored

[Akim Demaille]

While trying to use Emacs' time-stamp to use meaningful time stamps, I
had a @set command very high in the file, obviously too high:

/tmp % eof foo.texi                                              nostromo 15:39
: -------------------- foo.texi ----------------------
cat > foo.texi << \EOF
\input texinfo   @c -*-texinfo-*-
@c This date is automagically updated when you save this file:
@set lastupdate April 25, 2003

@c %**start of header
@setfilename sample.info

@set lastupdate2 April 25, 2003

@settitle Sample Manual 1.0

@set lastupdate3 April 25, 2003

@c %**end of header

@ifnottex
@node Top
@top GNU Sample
@end ifnottex

@menu
* First::
@end menu

@node First
@chapter First

@value{lastupdate}
@value{lastupdate2}
@value{lastupdate3}

@bye
EOF
: ------------------------------------------------------------
/tmp % makeinfo --no-header foo.texi                             nostromo 15:39
GNU Sample                          
**********

First
*****

   {Aucune valeur pour « lastupdate »} April 25, 2003 April 25, 2003



It looks like @set commands (and maybe other commands?) are ignored
before @setfilename.  Maybe makeinfo should warn about this?  Thanks
for Texinfo!