'a = 0 or a is null' should not be rewrite to a sarg 'a in (0, null)'

a = 0 or a is null -- returns true when a is null

a in (0, null) -- returns null when a is null

@Test void testSimplifyInOr() {
        or(
            gt(vInt(), literal(0)),
            isNull(vInt())),
        ">(?0.int0, 0)");
  }