Add blurb entry.

Author: markshannon

Misc/NEWS.d/next/Core and Builtins/2020-01-15-15-50-22.bpo-39320.oWARyk.rst

@@ -0,0 +1,12 @@
+
+Replace two complex bytecodes for building dicts with two simpler ones.
+
+The following bytecodes have been removed:
+
+* BUILD_MAP_UNPACK
+* BUILD_MAP_UNPACK_WITH_CALL
+
+The following three bytecodes have been added:
+
+* DICT_MERGE
+* DICT_UPDATE

Python/ceval.c

@@ -2827,6 +2827,7 @@ _PyEval_EvalFrameDefault(PyFrameObject *f, int throwflag)
                 goto error;
             }
             Py_DECREF(update);
+            PREDICT(CALL_FUNCTION_EX);
             DISPATCH();
         }