The parser wants to treat .float () foo; as a function returning a float
field, but qcc treats it as a field holding a function variable.
Fortuantely, field types are always "simple" (ie, at worst, just more
field type wrappers around the non-field type), so all that's needed to
obtain qcc grammar is to reach into the field type layers and do the
function type calculation based on the non-field type found there.
