move the class/c implementation into its own file

pkgs/compatibility-pkgs/compatibility-lib/mzlib/class.rkt

@@ -1,3 +1,4 @@
-(module class mzscheme
-  (require racket/private/class-internal)
-  (provide-public-names))
+#lang racket/base
+(require racket/private/class-internal
+         racket/private/class-c-old)
+(provide-public-names)

racket/collects/racket/class.rkt

@@ -5,7 +5,8 @@
   
 ;; All of the implementation is actually in private/class-internal.rkt,
 ;;  which provides extra (private) functionality to contract.rkt.
-(require "private/class-internal.rkt")
+(require "private/class-internal.rkt"
+         "private/class-c-old.rkt")
   
 (provide-public-names)
 (provide generic?)

racket/collects/racket/contract/private/object.rkt

@@ -8,6 +8,7 @@
          "blame.rkt"
          (for-syntax "opt-guts.rkt")
          racket/private/class-internal
+         racket/private/class-c-old
          racket/stxparam)
 
 (require (for-syntax racket/base))

racket/collects/racket/private/class-c-new.rkt

@@ -1,5 +1,6 @@
 #lang racket/base
 (require "class-internal.rkt"
+         "class-c-old.rkt"
          "../contract/base.rkt"
          "../contract/combinator.rkt"
          (only-in "../contract/private/guts.rkt"