Add a memcpy(a, a, n) test.

Add a memcpy(a, a, n) test.

clang depends on memcpy where src and dst are the same to actually
work. Even though this is, technically, undefined behavior,
clang is not going to change. Add a test to verify this assumption
holds true for android devices.

(cherry picked from commit 71766c25778fe13717259cdccb62463684794408)

Change-Id: I7d8ba4098729194dda69eab7070fd5c4ba1abbe9