[HarfBuzz] harfbuzz: Changes to 'rand'

[Behdad Esfahbod]

New branch 'rand' available with the following commits:
commit 14d1179ba4d5727f104e08f8ef44207265d570cc
Author: Behdad Esfahbod <behdad at behdad.org>
Date:   Mon Sep 10 16:24:52 2018 +0200

    Minor clean up of 'rand' patchset

commit f63cfe195bfaf7379c1ca87dd14b9595cd2834ec
Author: David Corbett <corbett.dav at husky.neu.edu>
Date:   Fri Feb 23 12:22:32 2018 -0500

    Don't seed the RNG from the contents of the buffer

commit 469fe78e2294042078fe97f434d14fd7caa4d4e2
Author: David Corbett <corbett.dav at husky.neu.edu>
Date:   Sat Jan 27 19:48:38 2018 -0500

    Test 'rand'

commit 0e28de0eed9753269c6d0340cba61fc4bf9ac385
Author: David Corbett <corbett.dav at husky.neu.edu>
Date:   Fri Jan 26 21:36:15 2018 -0500

    Allow requesting a specific glyph for 'rand'
    
    Randomization only happens by default. If the user specifies a value for
    'rand', that value is respected.

commit 0380ad4ce8fc182f8e540f150411efcec5fb53d1
Author: David Corbett <corbett.dav at husky.neu.edu>
Date:   Thu Jan 25 14:22:03 2018 -0500

    Implement 'rand'