Personally I don't recall ever having heard a newscaster on TV in the USA call
Demi Moore "Demmy", though perhaps once or twice I've heard a member of the general public say it that way. But I also often hear members of the general public saying "
Hayley"
Berry for
Halle Berry instead of "
Hallie", which is the way she pronounces it, and also how I remember all newscasters pronouncing
Halle.