Methods of the module object
Create a RecType, normalizing its contents.
Create a RecType, normalizing its contents. This means:
Nested Rec types on the type's spine are merged with the outer one. 2. Any refinement of the form
type T = z.Ton the spine of the type where
zrefers to the created rec-type is replaced by
type T. This avoids infinite recursions later when we try to follow these references.