Documenting make-hasheqv and using it

collects/compiler/zo-parse.rkt

@@ -794,9 +794,8 @@
                  [len (read-compact-number cp)])
              ((case eq
                 [(0) make-hasheq-placeholder]
-                ; XXX One of these should be eqv
                 [(1) make-hash-placeholder]
-                [(2) make-hash-placeholder])
+                [(2) make-hasheqv-placeholder])
               (for/list ([i (in-range len)])
                 (cons (read-compact cp)
                       (read-compact cp)))))]

collects/scribblings/reference/pairs.scrbl

@@ -1051,3 +1051,9 @@ for use with @scheme[make-reader-graph].}
 
 Like @scheme[make-immutable-hasheq], but produces a table placeholder
 for use with @scheme[make-reader-graph].}
+
+@defproc[(make-hasheqv-placeholder [assocs (listof pair?)])
+         hash-placeholder?]{
+
+Like @scheme[make-immutable-hasheqv], but produces a table placeholder
+for use with @scheme[make-reader-graph].}