anchor.diff:  (defclass immediate-ast (ast one-value-ast-mixin side-effect-free-ast-mixin)
     ((%value :initarg :value :reader value)))
   
  -(defun make-immediate-ast (value)
  -  (make-instance 'immediate-ast :value value))
  +(defun make-immediate-ast (value &key origin)
  +  (make-instance 'immediate-ast
  +    :origin origin
  +    :value value))
   
   (cleavir-io:define-save-info immediate-ast
     (:value value))
  
positive.code: (defclass symbol-value-ast (ast one-value-ast-mixin side-effect-free-ast-mixin)
    ((%symbol-ast :initarg :symbol-ast :reader symbol-ast)))
  
  (defun make-symbol-value-ast (symbol-ast)
    (make-instance 'symbol-value-ast :symbol-ast symbol-ast))
  
  (cleavir-io:define-save-info symbol-value-ast
    (:symbol-ast symbol-ast))
  
negative.code:        :type-specifier-ast value))
      value))
  
  (defun make-typeq-ast (form-ast type-specifier &key origin)
    (make-instance 'typeq-ast
      :origin origin
      :form-ast form-ast
      :type-specifier type-specifier))
  
  