bpo-37201: fix test_distutils failures for Windows ARM64 (GH-13902)

(cherry picked from commit daf62627518ad97ce66a48c49496aa0573cf0731)

Co-authored-by: Paul Monson <paulmon@users.noreply.github.com>
diff --git a/Lib/sysconfig.py b/Lib/sysconfig.py
index 8446c8d..e76e692 100644
--- a/Lib/sysconfig.py
+++ b/Lib/sysconfig.py
@@ -628,6 +628,8 @@
             return 'win-amd64'
         if '(arm)' in sys.version.lower():
             return 'win-arm32'
+        if '(arm64)' in sys.version.lower():
+            return 'win-arm64'
         return sys.platform
 
     if os.name != "posix" or not hasattr(os, 'uname'):