anchor.diff:  (defconstant +tag-fixnum-101+       #b1010)
   ;;#b1011
   (defconstant +tag-fixnum-110+       #b1100)
  -;;#b1101
  +(defconstant +tag-dx-root-object+   #b1101)
   (defconstant +tag-fixnum-111+       #b1110)
   (defconstant +tag-gc-forward+       #b1111)
   
  
positive.code: ;; be detected trivially: (eql (logand val #b111) 1)
  (defconstant +tag-cons+             #b0001)
  (defconstant +tag-fixnum-001+       #b0010)
  (defconstant +tag-dx-root-object+   #b0011)
  (defconstant +tag-fixnum-010+       #b0100)
  (defconstant +tag-immediate+        #b0101)
  (defconstant +tag-fixnum-011+       #b0110)
  
negative.code: reserved on the disk, but no specific block has been allocated.")
  (defconstant +block-map-id-not-allocated+ 0)
  
  (defparameter *llf-version* 36)
  
  (defconstant +llf-arch-x86-64+ 1)
  (defconstant +llf-arch-arm64+ 2)
  