[Bug plugins/56754] some missing plugin headers during installation in gcc 4.8

[baldrick at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56754

--- Comment #7 from Duncan Sands <baldrick at gcc dot gnu.org> ---
2013-05-21  Magnus Granberg  <baldr...@free.fr>

        PR plugins/56754
        * Makefile.in (PLUGIN_HEADERS): Add TARGET_H