fix *list/c so that it returns a flat contract when given flat contracts and a chaperone contract when given chaperone contracts

pkgs/racket-test/tests/racket/contract/flat-contracts.rkt

@@ -168,6 +168,7 @@
 
   (test-flat-contract '(listof boolean?) (list #t #f) (list #f 3 #t))
   (test-flat-contract '(listof any/c) (list #t #f) 3)
+  (test-flat-contract '(*list/c boolean? integer?) (list #t #f 1) (list #t #f))
 
   (test-flat-contract '(vectorof boolean? #:flat? #t) (vector #t #f) (vector #f 3 #t))
   (test-flat-contract '(vectorof any/c #:flat? #t) (vector #t #f) 3)

pkgs/racket-test/tests/racket/contract/list.rkt

@@ -205,5 +205,9 @@
    '((caddr (contract (*list/c (-> integer? integer?) (-> boolean? boolean?) (-> char? char?))
                       (list (λ (x) x) (λ (y) y) (λ (y) 'not-a-bool) (λ (y) y)) 'pos 'neg))
      #f))
+  (test/spec-passed/result
+   '*list/c8
+   '(chaperone-contract? (*list/c (-> integer? integer?) boolean?))
+   #t)
   
-  )
+  )

racket/collects/racket/contract/private/list.rkt

@@ -1025,8 +1025,8 @@
     #:property prop:custom-write custom-write-property-proc)
 
 (struct flat-*list/c *list-ctc ()
-  #:property prop:contract
-  (build-contract-property
+  #:property prop:flat-contract
+  (build-flat-contract-property
    #:trusted trust-me
    #:name *list/c-name-proc
    #:first-order *list/c-first-order
@@ -1037,8 +1037,8 @@
    #:late-neg-projection (λ (ctc) (*list/c-late-neg-projection ctc #f #t))
    #:list-contract? (λ (c) #t)))
 (struct chaperone-*list/c *list-ctc ()
-  #:property prop:contract
-  (build-contract-property
+  #:property prop:chaperone-contract
+  (build-chaperone-contract-property
    #:trusted trust-me
    #:name *list/c-name-proc
    #:first-order *list/c-first-order