kasan: add atomic tests

kasan: add atomic tests

Test that KASan can detect some unsafe atomic accesses.

As discussed in the linked thread below, these tests attempt to cover
the most common uses of atomics and, therefore, aren't exhaustive.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/all/[email protected]/T/#u
Signed-off-by: Paul Heidekrüger <[email protected]>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=214055
Acked-by: Mark Rutland <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>