Remove unnecessary cast

Author: mdboom

Python/ceval.c

@@ -765,9 +765,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
     /* Start instructions */
 #if !USE_COMPUTED_GOTOS
     dispatch_opcode:
-        // Cast to an 8-bit value to improve the code generated by MSVC
-        // (in combination with the EXTRA_CASES macro).
-        switch ((uint8_t)opcode)
+        switch (opcode)
 #endif
         {