bug#13931: 24.3.50; latest trunk fails to compile on linux

[Richard Kim]

Emacs trunk fails to compile on a fresh branch.
However compile succeeds if an older version is used.
Subsequent compilation of latest version also succeeds.
Details follow.

First attempt at compiling latest trunk fails via

    cd $SRC/emacs/emacs-trunk
    bzr pull --overwrite http://bzr.savannah.gnu.org/r/emacs/trunk
    cd ..
    bzr branch emacs-trunk emacs-trunk_20130311
    cd emacs-trunk_20130311
    ./configure --prefix /opt/local
    make all info

Above fails with    

    ...
    Loading loadup.el (source)...
    Using load-path ($SRC/emacs/emacs-trunk_20130311/lisp
    $SRC/emacs/emacs-trunk_20130311/lisp/emacs-lisp
    $SRC/emacs/emacs-trunk_20130311/lisp/language
    $SRC/emacs/emacs-trunk_20130311/lisp/international 
    $SRC/emacs/emacs-trunk_20130311/lisp/textmodes)
    Loading emacs-lisp/byte-run (source)...
    Symbol's function definition is void: \`

However if an older version is used, then the compile succeeds:

    bzr up -r 111990
    ./configure --prefix /opt/local
    make all info

Now going back to latest trunk version (which failed to compile earlier)
succeeds as well:

    bzr up
    ./configure --prefix /opt/local
    make all info

This problem showed up sometime after Feb 28, 2013.  I have been
compiling latest trunk once every week or so for a long time via the
same steps, which worked for me for several years until it started
failing in the past couple of weeks.

I use Ubuntu 12.04 on a 64-bit laptop.