gh-139122: Implement uuid6 in C with OS entropy and cached node IDs

Author: 1st1

Doc/whatsnew/3.16.rst

@@ -864,6 +864,10 @@ uuid
   (Contributed by Yury Selivanov in :gh:`139123`.)
 
 
+* :func:`uuid.uuid6` now has a C implementation, with a pure Python fallback.
+  (Contributed by Yury Selivanov in :gh:`160153`.)
+
+
 xml
 ---
 

Include/internal/pycore_global_objects_fini_generated.h

@@ -378,6 +378,7 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(check_same_thread)
         STRUCT_FOR_ID(clamp)
         STRUCT_FOR_ID(clear)
+        STRUCT_FOR_ID(clock_seq)
         STRUCT_FOR_ID(close)
         STRUCT_FOR_ID(closed)
         STRUCT_FOR_ID(closefd)
@@ -687,6 +688,7 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(newlines)
         STRUCT_FOR_ID(next)
         STRUCT_FOR_ID(nlocals)
+        STRUCT_FOR_ID(node)
         STRUCT_FOR_ID(node_depth)
         STRUCT_FOR_ID(node_offset)
         STRUCT_FOR_ID(nothing)