Remove most uses of mzscheme in the core.

Remaining are:
 - parts of unit200 that Matthew plans to remove.
 - the `mzscheme` implementation itself.

The implementation of `mzscheme` has been moved
to the `mzscheme` collection (from the `racket` and
`scheme` collections). The `scheme/mzscheme`
language, which was undocumented, has been removed.

This is slightly backwards-incompatible, because
the `xform` handling of precompiled headers now
evaluates code in a `racket/base`-like namespace,
instead of in a `mzscheme`-like namespace.

original commit: d54c1e4e4942c26dcbaaebcc43d5c92d507a8112

racket/lib/collects/mzlib/private/sigutil.rkt

@@ -1,4 +1,3 @@
-
 (module sigutil mzscheme
   ;; Used by unitsig.rkt
   ;; (needs an overhaul, too)

racket/lib/collects/mzscheme/main.rkt

@@ -1,3 +1,111 @@
+;;----------------------------------------------------------------------
+;; mzscheme: provide everything
 
-(module main scheme/mzscheme
+(module mzscheme '#%kernel
-  (provide (all-from scheme/mzscheme)))
+  (#%require racket/private/more-scheme
+             (all-except racket/private/misc
+			 collection-path
+			 collection-file-path)
+             racket/private/letstx-scheme
+             racket/private/stxcase-scheme
+             racket/private/stx
+             racket/private/qqstx
+             racket/private/define
+             mzscheme/private/stxmz-body
+             mzscheme/private/old-ds
+             mzscheme/private/old-rp
+             mzscheme/private/old-if
+             mzscheme/private/old-procs
+             racket/private/map ; shadows #%kernel bindings
+             racket/private/kernstruct
+             racket/private/promise
+             racket/private/cert
+             (only racket/private/cond old-cond)
+             ;; shadows #%kernel bindings:
+             (only racket/private/list 
+                   assq assv assoc reverse)
+             racket/private/member
+             racket/tcp
+             racket/udp
+             '#%builtin) ; so it's attached
+
+  (#%provide require require-for-syntax require-for-template require-for-label
+             provide provide-for-syntax provide-for-label
+             (all-from-except racket/private/more-scheme case old-case 
+                              log-fatal log-error log-warning log-info log-debug
+                              hash-update hash-update!)
+             (rename old-case case)
+             (all-from racket/private/misc)
+             collection-path
+             collection-file-path
+             (all-from-except racket/private/stxcase-scheme _ datum datum-case with-datum)
+             (all-from-except racket/private/letstx-scheme 
+                              -define -define-syntax -define-struct
+                              cond old-cond else =>)
+             (rename old-cond cond)
+             define-struct let-struct
+             identifier? ;; from racket/private/stx
+             (all-from racket/private/cert)
+             (all-from-except racket/private/qqstx quasidatum undatum undatum-splicing)
+             (all-from racket/private/define)
+             (all-from racket/private/kernstruct)
+             force delay promise?
+             (all-from-except '#%kernel #%module-begin #%datum 
+                              if make-empty-namespace
+                              syntax->datum datum->syntax
+                              free-identifier=?
+                              free-transformer-identifier=?
+                              free-template-identifier=?
+                              free-label-identifier=?
+                              vector-copy!
+                              thread-send
+                              thread-receive
+                              thread-try-receive
+                              thread-receive-evt
+                              make-hash make-immutable-hash make-weak-hash
+                              make-hasheq make-immutable-hasheq make-weak-hasheq
+                              hash? hash-eq? hash-weak?
+                              hash-ref hash-set! hash-set
+                              hash-remove! hash-remove 
+                              hash-copy hash-count
+                              hash-map hash-for-each 
+                              hash-iterate-first hash-iterate-next
+                              hash-iterate-value hash-iterate-key
+                              log-message log-level? make-logger logger? current-logger logger-name
+                              make-log-receiver log-receiver?
+                              prop:incomplete-arity)
+             (rename syntax->datum syntax-object->datum)
+             (rename datum->syntax datum->syntax-object)
+             (rename free-identifier=? module-identifier=?)
+             (rename free-transformer-identifier=? module-transformer-identifier=?)
+             (rename free-template-identifier=? module-template-identifier=?)
+             (rename free-label-identifier=? module-label-identifier=?)
+             (rename free-identifier=?* free-identifier=?)
+             make-hash-table hash-table? make-immutable-hash-table
+             (rename hash-ref hash-table-get)
+             (rename hash-set! hash-table-put!)
+             (rename hash-remove! hash-table-remove!)
+             (rename hash-count hash-table-count)
+             (rename hash-copy hash-table-copy)
+             (rename hash-map hash-table-map)
+             (rename hash-for-each hash-table-for-each)
+             (rename hash-iterate-first hash-table-iterate-first)
+             (rename hash-iterate-next hash-table-iterate-next)
+             (rename hash-iterate-value hash-table-iterate-value)
+             (rename hash-iterate-key hash-table-iterate-key)
+             namespace-transformer-require
+             transcript-on transcript-off
+             (rename cleanse-path expand-path)
+             (rename if* if)
+             (rename list list-immutable)
+             make-namespace
+             #%top-interaction
+             map for-each andmap ormap
+             assq assv assoc reverse memq memv member
+             (rename old-datum #%datum)
+             (rename mzscheme-in-stx-module-begin #%module-begin)
+             (rename #%module-begin #%plain-module-begin)
+             (rename lambda #%plain-lambda)
+             (rename #%app #%plain-app)
+	     (all-from racket/tcp)
+             (all-from racket/udp)))

racket/lib/collects/mzscheme/private/old-ds.rkt

@@ -1,8 +1,8 @@
 
 (module old-ds '#%kernel
-  (#%require "define-struct.rkt"
+  (#%require racket/private/define-struct
              (for-syntax '#%kernel
-                         "stxcase-scheme.rkt"))
+                         racket/private/stxcase-scheme))
 
   (#%provide define-struct let-struct old-datum)
   

racket/lib/collects/mzscheme/private/old-procs.rkt

@@ -1,21 +1,47 @@
 
 (module old-procs '#%kernel
-  (#%require "small-scheme.rkt"
+  (#%require racket/private/small-scheme
-             "more-scheme.rkt"
+             racket/private/more-scheme
-             "define.rkt"
+             racket/private/define
-             "member.rkt")
+             racket/private/member
+	     (only racket/private/misc collection-path collection-file-path))
 
   (#%provide make-namespace
              free-identifier=?*
              namespace-transformer-require
              transcript-on
              transcript-off
+	     (rename new:collection-path collection-path)
+	     (rename new:collection-file-path collection-file-path)
              make-hash-table
              make-immutable-hash-table
              hash-table?)
 
   (define reflect-var #f)
 
+  (define new:collection-path
+    (let ([collection-path (lambda (collection . collections)
+                             (apply collection-path
+                                    (lambda (s)
+                                      (raise
+                                       (exn:fail:filesystem
+                                        (string-append "collection-path: " s)
+                                        (current-continuation-marks))))
+                                    collection collections))])
+      collection-path))
+
+  (define new:collection-file-path
+    (let ([collection-file-path (lambda (file-name collection . collections)
+                                  (apply collection-file-path
+                                         (lambda (s)
+                                           (raise
+                                            (exn:fail:filesystem
+                                             (string-append "collection-file-path: " s)
+                                             (current-continuation-marks))))
+                                         file-name collection collections))])
+      collection-file-path))
+
+  
   (define make-namespace
     (case-lambda
      [() (make-namespace 'initial)]

racket/lib/collects/mzscheme/private/old-rp.rkt

@@ -1,6 +1,7 @@
 
 (module old-rp '#%kernel
-  (#%require (for-syntax '#%kernel "stx.rkt" "small-scheme.rkt" "stxcase-scheme.rkt"))
+  (#%require (for-syntax '#%kernel racket/private/stx racket/private/small-scheme
+			 racket/private/stxcase-scheme))
 
   (#%provide require require-for-syntax require-for-template require-for-label
              provide provide-for-syntax provide-for-label)

racket/lib/collects/mzscheme/private/stxmz-body.rkt

@@ -2,8 +2,9 @@
 ;; mzscheme's `#%module-begin'
 
 (module stxmz-body '#%kernel
-  (#%require "define.rkt"
+  ;; These could probably change to just be `(require racket/base)`.
-             (for-syntax '#%kernel "stx.rkt"))
+  (#%require racket/private/define
+             (for-syntax '#%kernel racket/private/stx))
 
   ;; So that expansions print the way the Racket programmer expects:
   (#%require (rename '#%kernel #%plain-module-begin #%module-begin))
@@ -16,7 +17,7 @@
 	   (list* (quote-syntax #%plain-module-begin)
                   (datum->syntax
 		   stx
-                   (list (quote-syntax #%require) '(for-syntax scheme/mzscheme)))
+                   (list (quote-syntax #%require) '(for-syntax mzscheme)))
 		  (stx-cdr stx))
 	   stx)
 	  (raise-syntax-error #f "bad syntax" stx))))