Modified hl-machine-hash again, this time taking advantage of CCL
utility ccl::strip-tag-to-fixnum, which Gary Byers says always returns
a fixnum that essentially just strips the low four bits from
ccl::%address-of.

Added comments and a trivial fixnum check, based on emails from Gary
Byers.

Quoting :doc note-6-5:

  The utilities hons-shrink-alist and hons-shrink-alist! have
  essentially been renamed to [fast-alist-fork] and
  [fast-alist-fork!], respectively. The old names are deprecated but
  remain as macros that are macro-aliases for the respective new
  names (see [macro-aliases-table]). New utilities,
  [fast-alist-clean] and [fast-alist-clean!] are similar to the above
  but take just one argument and, if it is a fast alist, associates
  the result with the hash table link of that argument. Thanks to
  Jared Davis for providing a concrete proposal, together with the
  new names, for what had been only a concept.


git-svn-id: http://acl2-devel.googlecode.com/svn/trunk@1324 5d84a466-a78b-0930-a311-59b22171a541
Trivial update (not even updating acl2-startup-info.txt)
to get rid of "property changes" shown below.

% svn diff

Property changes on: .
___________________________________________________________________
Modified: svn:mergeinfo
   Merged /branches/centaur:r1322

% 


git-svn-id: http://acl2-devel.googlecode.com/svn/trunk@1325 5d84a466-a78b-0930-a311-59b22171a541
Comment changes only.  Incorporates updates from J, tweaked by me in
consultation with Jared.


git-svn-id: http://acl2-devel.googlecode.com/svn/trunk@1327 5d84a466-a78b-0930-a311-59b22171a541
Fixed a bug in hons-clear and hons-wash that was failing to free up to
two fast alists.  Thanks to Jared Davis for providing a fix.


git-svn-id: http://acl2-devel.googlecode.com/svn/trunk@1328 5d84a466-a78b-0930-a311-59b22171a541