install broken for treelang

[Matthias Klose]

This patch breaks installation of treelang:

2003-10-06  Mark Mitchell  <mark@codesourcery.com>

        * Make-lang.in (treelang.info): Replace with ...
        (info): ... this.
        * Make-lang.in (treelang.dvi): Replace with ...
        (dvi): ... this.

make[3]: *** No rule to make target `treelang.info', needed by
`treelang.install-info'.  Stop.
make[3]: Leaving directory `/build/gcc/snap/gcc-20031011/build/gcc'
make[2]: *** [install-gcc] Error 2