Add a NEWS entry.

ericsnowcurrently · ericsnowcurrently · commit 6cae5e09db27 · 2021-06-14T11:27:21.000-06:00
diff --git a/Misc/NEWS.d/next/Core and Builtins/2021-06-07-15-13-44.bpo-43693.c_zDeY.rst b/Misc/NEWS.d/next/Core and Builtins/2021-06-07-15-13-44.bpo-43693.c_zDeY.rst
@@ -0,0 +1,4 @@
+Computation of the offsets of cell variables is done in the compiler instead
+of at runtime. This reduces the overhead of handling cell and free
+variables, especially in the case where a variable is both an argument and
+cell variable.
