Fix up constructor checks for conditional mov and friends.

Author: dvanhorn

langs/a86/ast.rkt

@@ -30,12 +30,12 @@
     (values a x)))
 
 (define check:cmov
-  (λ (a1 a2 n)
+  (λ (a a1 a2 n)
     (unless (register? a1)
       (error n "expects register; given ~v" a1))
     (unless (or (register? a2) (offset? a2))
       (error n "expects register or offset; given ~v" a2))
-    (values a1 a2)))
+    (values a a1 a2)))
 
 (define check:arith  
   (λ (a a1 a2 n)