package—a package designator.
use-list—a list of package objects.
Returns a list of other packages used by package.
(package-use-list (make-package 'temp)) → (#<PACKAGE "COMMON-LISP">) (use-package 'common-lisp-user 'temp) → T (package-use-list 'temp) → (#<PACKAGE "COMMON-LISP"> #<PACKAGE "COMMON-LISP-USER">)
Should signal an error of type type-error
if package is not a package designator.