Append subset of one array to another array
#include <array.h>
void array_cate(array* x,array* y, int64 pos,int64 stop);
array x; array y; int64 pos; int64 stop; array_cate(&x,y,pos,stop);
array_cate is like array_cat, but uses only byte positions pos through stop-1 in y. It fails if pos negative, or if stop is smaller than pos, or if the number of initialized bytes in y is smaller than stop.