I've written "He", because in the song, the Sun is like a person (that's why I've written "the Sun", not "the sun"). That's why I've taken the liberty to use the word "He", instead of "It".
Moreover, the Sun is frequently compared to God... and because Religious leaders are men, God is surely a male...
If God = Sun and God = He ==> Sun = He
... And you're right, "Sun" is a male name in French.
