Hello, cffi-devel!

I have found a case when cffi behaves not as documented. The documentation in page for define-foreign-library says about load-clauses list that "Finally, if feature is t, this load-clause is picked unconditionally."

But the load-clause with feature set to T is ignored, because function %foreign-library-spec uses alexandria:featurep, which does consider T to be feature.

This patch should fix this: to return the load-clause that has feature set to T.

Test case: (define-foreign-library libgraphan-wrap (t (:default "libgraphan-wrap")))

(equal (%foreign-library-spec (get-foreign-library 'libgraphan-wrap)) (t (:default "libgraphan-wrap"))) => T