look past comments in a public form's header

tests/modules/greet.sex

@@ -7,7 +7,11 @@
 
 (include stdio.h)
 
-(pub var greet-count int 0)
+(pub var greet-count ;; a comment in the header of a public form is
+                     ;; not part of it: what the importer is given has
+                     ;; to be `extern int greet-count', not a form
+                     ;; counted off by one
+  int 0)
 
 (pub struct greeting ((text (* const char)) (times int)))
 
@@ -23,7 +27,8 @@
            (lambda (name field-type)
              `(printf "%s " ,(symbol->string name))))))
 
-(pub fn greet ((name (* const char))) void
+(pub fn greet ;; ...and here the prototype would lose its return type
+  ((name (* const char))) void
   (++ greet-count)
   (printf "hello, %s\n" name))