Add John Regehr to Misc/ACKS for his help with finding integer overflows (issue #9530).

mdickinson · mdickinson · commit aeb562ee5f3c · 2012-05-07T10:37:37.000+01:00
diff --git a/Misc/ACKS b/Misc/ACKS
@@ -836,6 +836,7 @@ Terry Reedy
 Gareth Rees
 Steve Reeves
 Lennart Regebro
+John Regehr
 Federico Reghenzani
 Ofir Reichenberg
 Sean Reifschneider
