anchor.diff:    (accumulated-toplevel-expressions nil)
     (predefined-symbols       nil)
   
  -  ; Literals that must be declared or cached before code containing them is emitted.
  -  (compiled-chars           (make-hash-table :test #'==))
  -  (compiled-numbers         (make-hash-table :test #'==))
  -  (compiled-strings         (make-hash-table :test #'eq))
     (compiled-symbols         (make-hash-table :test #'eq))
  +  ; Old C core.
  +;  (compiled-chars           (make-hash-table :test #'==))
  +;  (compiled-numbers         (make-hash-table :test #'==))
  +;  (compiled-strings         (make-hash-table :test #'eq))
   
     (compiled-decls           nil)
     (compiled-inits           nil)
  
positive.code:   ;;; For users.
    ;;;
  
    ; Include low-level assertions.
    (assert?                    nil)
  
    ; Backtrace stack at run-time.
    (backtrace?                 nil)
  
    ; Also generate argument expanders for functions with simple
    ; argument lists for optional assertions.
    (always-expand-arguments?   nil)
  
    ; Import functions from the compile-time host if missing.
    (import-from-host?          t)
  
    ; Also import global variables from the compile-time host if missing.
    (import-variables?          t)
  
    ; Dump outputs of all passes if T.  Might also be a pass name or a list
  
negative.code:         :accumulated-toplevel-expressions (copy-list accumulated-toplevel-expressions)
          :predefined-symbols       (copy-list predefined-symbols)
  
          :compiled-symbols         (copy-hash-table compiled-symbols)
  ;        :compiled-chars           (copy-hash-table compiled-chars)
  ;        :compiled-numbers         (copy-hash-table compiled-numbers)
  ;        :compiled-strings         (copy-hash-table compiled-strings)
          :compiled-decls           (copy-list compiled-decls)
          :compiled-inits           (copy-list compiled-inits)
          :identifiers              (copy-hash-table identifiers)
  