Famed Irish singer Sinéad O’Connor has a new religion and a new name. The artist, best known for her 1990 star-making cover tune, “Nothing Compares 2 U,” now counts herself among the nearly 2 billion Muslims worldwide and has adopted the name Shuhada’ Davitt. Clad in a long-sleeved shirt and a headscarf, called a hijab, the new convert accepted Islam …