Constraints for numeric unboxed types

[dahlia]

E.g.:

@numeric-constraints(min=1, max=12)
unboxed month (int32);

Possible options:

• min (inclusive; cannot be used with greater-than): Add numeric-constraints annotation #271
• max (inclusive; cannot be used with less-than): Add numeric-constraints annotation #271
• greater-than (exclusive; cannot be used with min)
• less-than (exclusive; cannot be used with max)