Removed special handling of `ceylon.promise` for the JS backend (#406)
Removed special handling of `ceylon.promise` for the JS backend (#406)

jeancharles-roger/ceylon-sdk,matejonnet/ceylon-sdk,vietj/ceylon-sdk,jeancharles-roger/ceylon-sdk,ASzc/ceylon-sdk,rohitmohan96/ceylon-sdk,vietj/ceylon-sdk,ASzc/ceylon-sdk