From d90dbbfd571c8092d624ac01fe00f123ef3061dd Mon Sep 17 00:00:00 2001
From: AlexKnauth <alexander@knauth.org>
Date: Thu, 20 Apr 2017 22:44:12 -0700
Subject: [PATCH] attach orig-binding property (used for occurrence typing)

---
 macrotypes/typecheck.rkt | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/macrotypes/typecheck.rkt b/macrotypes/typecheck.rkt
index bd554755..0cd698da 100644
--- a/macrotypes/typecheck.rkt
+++ b/macrotypes/typecheck.rkt
@@ -948,7 +948,8 @@
                 (let*-syntax ([X (make-variable-like-transformer
                                  (mk-tyvar (attach #'X ':: (#,kev #'#%type))))] ...
                               [x (make-variable-like-transformer
-                                  (attachs #'x '(sep ...) #'(τ ...)
+                                  (attachs (attach #'x 'orig-binding #'x)
+                                           '(sep ...) #'(τ ...)
                                            #:ev #,tev))] ...)
                   (#%expression e) ... void)))))
        (list #'tvs+ #'xs+