Remove cases from ceval.c -- they are no longer needed

Author: gvanrossum

Python/bytecodes.c

@@ -29,6 +29,10 @@ dummy_func(
 {
     switch (opcode) {
 
+        /* BEWARE!
+           It is essential that any operation that fails must goto error
+           and that all operation that succeed call DISPATCH() ! */
+
 // BEGIN BYTECODES //
         // stack effect: ( -- )
         inst(NOP) {