Merge 3.5 (issue #25887)

diff --cc Doc/reference/datamodel.rst
Simple merge

diff --cc Misc/NEWS
index d51c3f31327923cf9fe8723e7275db6fa13f77ad,4243a050f111f2423a1b59cb83a68b5f3fe3a6c1..895325e4fe1ea33fb44872df3fb3aab74984fd28
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -174,12 -69,10 +174,15 @@@ Core and Builtin
  
  - Issue #25660: Fix TAB key behaviour in REPL with readline.
  
 -
 +- Issue #26288: Optimize PyLong_AsDouble.
 +
 +- Issues #26289 and #26315: Optimize floor and modulo division for
 +  single-digit longs.  Microbenchmarks show 2-2.5x improvement.  Built-in
 +  'divmod' function is now also ~10% faster.
 +
+ - Issue #25887: Raise a RuntimeError when a coroutine object is awaited
+   more than once.
+ 
  Library
  -------
  

diff --cc Objects/genobject.c
Simple merge