The attached patch removed unreachable code after RAISE_VARARGS, BREAK_LOOP and RETURN_VALUE in generic way (no more tests for LOAD_CONST None RETURN_VALUE, etc.)

It is possible to generalize it more for some other bytecodes.  The only problem they are already used in switch() in question as labels.  Probably not important enough to warrant another switch() or break this out into a function/macro.

No speedup is expected, but I think the patch is good with no drawbacks anyway.