DEFINE-SETF-EXPANDER is not implemented

[robert-strandh]

The form (define-setf-expander f (x) (declare (inline f))) gives a parse error indicating
that the declaration is not allowed at that point, but I think the syntax is valid.

[scymtym]

This is because define-setf-expander is not yet implemented which causes the form in question to be parsed as a function application.