mi/match: fix dtree construction order of or-pattern When we have a match statement such as     match x     | `std.Some _ || _:     ;;
mi/match: fix dtree construction order of or-pattern
When we have a match statement such as
    match x
    | `std.Some _ || _:
    ;;

the order of the patterns `std.seom _ and _ matters.
before the fix, we would get false positive of "pattern
matched by earlier case".

Signed-off-by: Mura Li <6b680b8d78548d868385c7f24c7e2dd25dd03b94@ctli.io>

oridb/mc,oridb/mc,oridb/mc,oridb/mc