[roots_mod.c] more changes, small speedup for r=3, now works for d<=10
[roots_mod.c] more changes, small speedup for r=3, now works for d<=10

mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs