Apparently, GNU make 3.81 picks the generic '%.h' rule instead of the
more specific 'rpc/%.h' rule during the preparation of the libc.
Changing the order of the rules solves the problem.
Certain rpc headers are needed for compiling getaddrinfo.c. Unfortunatly
that means we have to generate _a few_ header files which we do when we
prepare the libc.
These header files need to be created before the symlinks. Also, some of
these header files depend on a patch. Therefore we apply the patches
first, generate the header files and in the end we create the symlinks.
Fixes#296.
We are using bison to generate certain files when preparing the libc.
However the yacc(1) wrapper script is used instead of calling bison
directly which does not work if bison is not installed but the original
yacc(1).
Fixes#225. Fixes#227.
