bpo-31961: Fix support of path-like executables in subprocess.

Doc/library/subprocess.rst

@@ -339,12 +339,12 @@ functions.
    the class uses the Windows ``CreateProcess()`` function.  The arguments to
    :class:`Popen` are as follows.
 
-   *args* should be a sequence of program arguments or else a single string.
-   By default, the program to execute is the first item in *args* if *args* is
-   a sequence.  If *args* is a string, the interpretation is
-   platform-dependent and described below.  See the *shell* and *executable*
-   arguments for additional differences from the default behavior.  Unless
-   otherwise stated, it is recommended to pass *args* as a sequence.
+   *args* should be a sequence of program arguments or else a single string or
+   :term:`path-like object`. By default, the program to execute is the first
+   item in *args* if *args* is a sequence. If *args* is a string, the
+   interpretation is platform-dependent and described below.  See the *shell*
+   and *executable* arguments for additional differences from the default
+   behavior.  Unless otherwise stated, it is recommended to pass *args* as a sequence.
 
    On POSIX, if *args* is a string, the string is interpreted as the name or
    path of the program to execute.  However, this can only be done if not
@@ -558,6 +558,10 @@ functions.
       Popen destructor now emits a :exc:`ResourceWarning` warning if the child
       process is still running.
 
+   .. versionchanged:: 3.7
+      *args*, or the first element of *args* if *args* is a sequence, can now
+      be a :term:`path-like object`.
+
 
 Exceptions
 ^^^^^^^^^^

Misc/NEWS.d/3.7.0b1.rst

@@ -630,7 +630,6 @@ Add contextlib.AsyncExitStack. Patch by Alexander Mohr and Ilya Kulakov.
 .. nonce: x5Sv0R
 .. section: Library
 
-*Removed in Python 3.7.0b2.*
 The *args* argument of subprocess.Popen can now be a :term:`path-like
 object`. If *args* is given as a sequence, it's first element can now be a
 :term:`path-like object` as well.