Fixed type in utility _memory_overlap. (#770)

To intervals [B1..E1) and [B2..E2) do not overlap when
E1 <= B2 || E2 <= B1 <=> B1 >= E2 || B2 >= E1.

Hence the overlap may occur is (B1 < E2) and (B2 < E1).

Author: oleksandr-pavlyk

dpctl/tensor/_copy_utils.py

@@ -75,7 +75,8 @@ def _has_memory_overlap(x1, x2):
             p1_end = p1_beg + m1.nbytes
             p2_beg = m2._pointer
             p2_end = p2_beg + m2.nbytes
-            return p1_beg > p2_end or p2_beg < p1_end
+            # may intersect if not ((p1_beg >= p2_end) or (p2_beg >= p2_end))
+            return (p1_beg < p2_end) and (p2_beg < p1_end)
         else:
             return False
     else: