Issue #28676: merge from 3.6

diff --cc Misc/NEWS
index 161de763e92a64649b667820735c0af3e5860d1c,59785c3785c19e7f3900769e183d3381701c6eae..352bbf756a71fe3589fc85e3e10f50292726d2b3
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -437,17 -468,6 +437,20 @@@ Buil
  - Issue #15819: Remove redundant include search directory option for building
    outside the source tree.
  
++- Issue #28676: Prevent missing 'getentropy' declaration warning on macOS.
++  Patch by Gareth Rees.
++
 +Tools/Demos
 +-----------
 +
 +- Issue #15369: The pybench and pystone microbenchmark have been removed from
 +  Tools. Please use the new Python benchmark suite
 +  https://github.com/python/performance which is more reliable and includes a
 +  portable version of pybench working on Python 2 and Python 3.
 +
 +- Issue #28102: The zipfile module CLI now prints usage to stderr.
 +  Patch by Stephen J. Turnbull.
 +
  Tests
  -----