Issue #21704: Merge.

diff --cc Misc/ACKS
Simple merge

diff --cc Misc/NEWS
index 851e9258d62330bb007f8a8063c7b7d045b284d0,92c9cb61bdb070e5b5dfe16c48ef18498bcc7f97..fa36c6b8a5747a39c50a76ff0e18abfec4aa1ec3
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -113,9 -27,9 +113,12 @@@ Core and Builtin
  Library
  -------
  
+ - Issue #21704: Fix build error for _multiprocessing when semaphores
+   are not available.  Patch by Arfrever Frehtes Taifersar Arahesis.
+ 
 +- Issue #20173: Convert sha1, sha256, sha512 and md5 to ArgumentClinic.
 +  Patch by Vajrasky Kok.
 +
  - Fix repr(_socket.socket) on Windows 64-bit: don't fail with OverflowError
    on closed socket. repr(socket.socket) already works fine.