glibc in Fedora is currently configured with `--enable-obsolete-rpc',
so I guess we can see which way the wind is blowing.
(1) This changes our configure script to prefer libtirpc if it is
available.
If libtirpc is _not_ available then:
(a) Headers must be located in <rpc/xdr.h>, or the user must supply
the right CFLAGS.
(b) XDR functions must be located in one of -lportablexdr, -lrpc,
-lxdr, -lnsl or no library at all (ie. -lc), and the user must set
LDFLAGS if needed.
(2) We no longer add these paths automatically to $(CFLAGS)/$(LIBS).
Any part of libguestfs which needs <rpc/*.h> or the xdr_* functions
must use $(RPC_CFLAGS)/$(RPC_LIBS) explicitly.
(3) Previously Mac OS X had a workaround for the broken 64 bit support
in the supplied rpcgen. This workaround "activates" all the time if
you use tirpc, so breaking Linux after the above changes. tirpc is
supported on OS X, so I think it's just better to use that rather than
the broken rpcgen. For that reason I removed the workaround
completely.
Thanks: Roy Keene