Issue #23738: Merge 3.5 into 3.6

diff --cc Doc/library/os.rst
Simple merge

diff --cc Lib/test/test_os.py
Simple merge

diff --cc Modules/clinic/posixmodule.c.h
index a7045a87bcfb1096c83b533fe9a44abf853dad7b,9ef702a297f923f350d0dbdafe95e075a75c026b..a48de6ac882b2b28705375d760e4088fa6f65e69
--- 1/Modules/clinic/posixmodule.c.h
--- 2/Modules/clinic/posixmodule.c.h
+++ b/Modules/clinic/posixmodule.c.h
@@@ -5792,4 -5788,4 +5792,4 @@@ exit
  #ifndef OS_SET_HANDLE_INHERITABLE_METHODDEF
      #define OS_SET_HANDLE_INHERITABLE_METHODDEF
  #endif /* !defined(OS_SET_HANDLE_INHERITABLE_METHODDEF) */
- /*[clinic end generated code: output=35b50461dbecd65d input=a9049054013a1b77]*/
 -/*[clinic end generated code: output=95824c52fd034654 input=a9049054013a1b77]*/
++/*[clinic end generated code: output=a5c9bef9ad11a20b input=a9049054013a1b77]*/

diff --cc Modules/posixmodule.c
Simple merge