According to this resolved spec issue:
w3c/csswg-drafts#2140,
we retire the 3-valued <position> on
1. `object-position`
2. `perspective-origin`,
3. `mask-position`
4. `circle()` and `ellipse()`
, but still keep the support for `background-position`.

Besides, I simply run this python script to generate the .ini file:
```
s = sys.argv[1] + ".ini"
with open(s, "w") as f:
    f.write('[{}]\n'.format(sys.argv[1]))
    f.write('  expected: FAIL\n')
    f.write('  bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1559276\n')
```

Differential Revision: https://phabricator.services.mozilla.com/D37126