The previous patch failed with icedtea-6, which has uncatched
'decoding-error' in addition to 'encoding-error'.

And it seems that only icedtea-8 needs patch, since in icedtea-7
the USE_SYSTEM_GTK, USE_SYSTEM_FONTCONFIG, etc make it links with
those libraries instead of dlopen them.

So, now only patch icedtea-8: