Order matters on inheritance

[JS]

I don't know what the expected behavior is but it seems odd/wrong:

http://dpaste.dzfl.pl/a390f1f4

Note that there are two issues here(almost the same). First is 
that A.foo isn't called and second is that the order of 
inheritance on A matters(: X, Y vs : Y,X).


I would expect that A.foo(A) should match first and the ambiguity 
created from the inheritance should result in an error.