Add an rpcgen implementation

RHEL-8 has removed rpcgen from it's distribution and does not
support the code. Add our own implementation of rpcgen to
ensure we can build DSOS on all platforms.

rpcgen/Makefile.am

@@ -0,0 +1,12 @@
+CLEANFILES = *~
+
+bin_PROGRAMS = rpcgen
+man_MANS = rpcgen.1
+
+EXTRA_DIST=${MANS}
+
+noinst_HEADERS = proto.h rpc_parse.h rpc_scan.h rpc_util.h
+
+rpcgen_SOURCES = rpc_clntout.c rpc_cout.c rpc_hout.c rpc_main.c \
+	rpc_parse.c rpc_sample.c rpc_scan.c rpc_svcout.c rpc_tblout.c \
+	rpc_util.c

rpcgen/proto.h

@@ -0,0 +1,65 @@
+/****** rpc_clntout.c ******/
+
+void write_stubs(void);
+void printarglist(proc_list *proc, const char *result,
+		  const char *addargname, const char *addargtype);
+
+/****** rpc_cout.c ******/
+
+void emit (definition *def);
+
+/****** rpc_hout.c ******/
+
+void print_datadef(definition *def);
+void print_funcdef(definition *def);
+void pxdrfuncdecl(const char *name, int pointerp);
+void pprocdef(proc_list *proc, version_list *vp,
+	      const char *addargtype, int server_p, int mode);
+void pdeclaration(const char *name, declaration *dec, int tab,
+		  const char *separator);
+void print_xdr_func_def (char* name, int pointerp, int i);
+
+/****** rpc_main.c ******/
+	/* nil */
+
+/****** rpc_parse.c ******/
+definition *get_definition(void);
+
+/****** rpc_sample.c ******/
+void write_sample_svc(definition *def);
+int write_sample_clnt(definition *def);
+void add_sample_msg(void);
+void write_sample_clnt_main(void);
+
+/****** rpc_scan.c ******/
+   /* see rpc_scan.h */
+
+/****** rpc_svcout.c ******/
+int nullproc(const proc_list *proc);
+void write_svc_aux(int nomain);
+void write_msg_out(void);
+
+/****** rpc_tblout.c ******/
+void write_tables(void);
+
+/****** rpc_util.c ******/
+void reinitialize(void);
+int streq(const char *a, const char *b);
+void error(const char *msg) __attribute__ ((noreturn));
+void crash(void) __attribute__ ((noreturn));
+void tabify(FILE *f, int tab);
+char *make_argname(const char *pname, const char *vname);
+void add_type(int len, const char *type);
+
+/* This header is the last one included in all rpc_*.c files,
+   so we define stuff for cross-rpcgen here to avoid conflicts with
+   $build's C library and $host's glibc.  */
+
+#ifdef IS_IN_build
+
+/* Disable translated messages when built for $build and used in
+   building glibc.  */
+#define _(X) (X)
+#define textdomain(X) ((void) 0)
+
+#endif