mm/damon/core-test: test damon_set_regions

mainline inclusion
from mainline-v6.2-rc6
commit 62f40956
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I6MRUG

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=62f409560eb235ad9c2c9dbe1a3a57801431da5a

--------------------------------

Preceding commit fixes a bug in 'damon_set_regions()', which allows holes
in the new monitoring target ranges.  This commit adds a kunit test case
for the problem to avoid any regression.

Link: https://lkml.kernel.org/r/20220909202901.57977-4-sj@kernel.org


Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Yun Levi <ppbuk5246@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ze Zuo <zuoze1@huawei.com>