For each active attribute (ref/const/nogc/etc) call fp with a void* for the work param and a string representation of the attribute.
'args' are being matched to function 'this' Determine match level. Input: flag 1 performing a partial ordering match
Return true if there are lazy parameters.
Examine function signature for parameter p and see if p can 'escape' the scope of the function.
Do this lazily, as the parameter types might be forward referenced.
For TypeFunction, nextOf() can return NULL if the function return type is meant to be inferred, and semantic() hasn't yet ben run on the function. After semantic(), it must no longer be NULL.