restore *.orig.c to each entry

Under each yyyy/dir there is a file of the form '*.orig.c'
containing the original source code, or as close as we can
get to the original source code.

2000/natori/natori.orig.c

@@ -0,0 +1,3 @@
+#include <stdio.h>
+#include <math.h>
+double l;main(_,o,O){return putchar((_--+22&&_+44&&main(_,-43,_),_&&o)?(main(-43,++o,O),((l=(o+21)/sqrt(3-O*22-O*O),l*l<4&&(fabs(((time(0)-607728)%2551443)/405859.-4.7+acos(l/2))<1.57))[" #"])):10);}