The in the following Ada example, the package instantiation causes SlickEdit to not display the procedure "dump_all" in the Defs window. Change package to packagex and SE works correctly (though it wouldn't be valid Ada).
procedure dump_all is
package int_int_io is new Text_IO.Integer_IO(Integer);
begin -- dump_all
null;
end dump_all;
SlickEdit Pro 2018 (v23.0.1.1 64-bit)
Windows and Linux