* opc2c.c: Include "libiberty.h" and <errno.h>.

    * opc2c.c: Include "libiberty.h" and <errno.h>.
        (orig_filename): Constify.
        (dump_lines): Fix line number directive.
        (main): Set orig_filename to basename of input file.  Use
        xstrerror.

        * Makefile.am (rx-dis.lo): Remove explicit dependencies.
        ($(srcdir)/rx-decode.c): Use @MAINT@.  Use $(EXEEXT_FOR_BUILD)
        instead of $(EXEEXT).
        (opc2c$(EXEEXT_FOR_BUILD)): Renamed from opc2c$(EXEEXT) and use
        $(LINK_FOR_BUILD).  Link with libiberty.
        (MOSTLYCLEANFILES): Add opc2c$(EXEEXT_FOR_BUILD).
        (MAINTAINERCLEANFILES): Add $(srcdir)/rx-decode.c.
        * Makefile.in: Regenerated.
        * rx-decode.c: Regenerated.