How can I make it simple?
Power of Sun >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> Durability of Wolverine outside his skeleton.
Everything except his skeleton will be burned to ashes. You can't deny reality. Unlike his previous appearences in comics, we try to follow the laws of reality in some way here (etc. Batman could not survive hit from Superman, unlike comics have showed, since he is normal human.) Therefore, Wolverine can't survive full power blast from Havok. Because his skin, muscles, organs and brains have normal human durability. Bullets and knifes pass them.
And Wolverine would also be burned to ashes if Torch would go nova.