fix #15686, skip comments before first line number in type expressions

Author: JeffBezanson

src/julia-parser.scm

@@ -1172,7 +1172,9 @@
           (if (reserved-word? (peek-token s))
               (error (string "invalid type name \"" (take-token s) "\"")))
           (let ((sig (parse-subtype-spec s))
-                (loc (line-number-node s)))
+                (loc (begin (if (newline? (peek-token s))
+                                (skip-ws-and-comments (ts:port s)))
+                            (line-number-node s))))
             (begin0 (list 'type (if (eq? word 'type) #t #f)
                           sig (add-filename-to-block! (parse-block s) loc))
                     (expect-end s word)))))