[Patches] Support for EXTENDED_ARG, fixes for bugs open/32 and open/134

[Tim Peters]

[Charles G Waldman]
> ...
> *** 643,652 ****
>   #if defined(Py_DEBUG) || defined(LLTRACE)
>   		f->f_lasti = INSTR_OFFSET();
>   #endif
> -
>   		opcode = NEXTOP();
> ! 		if (HAS_ARG(opcode))
>   			oparg = NEXTARG();
>   #ifdef DYNAMIC_EXECUTION_PROFILE
>   #ifdef DXPAIRS
>   		dxpairs[lastopcode][opcode]++;
> --- 645,660 ----
>   #if defined(Py_DEBUG) || defined(LLTRACE)
>   		f->f_lasti = INSTR_OFFSET();
>   #endif
>   		opcode = NEXTOP();
> ! 		if (HAS_ARG(opcode)) {
>   			oparg = NEXTARG();
> + 			if (IS_EXTENDED()) {
> + 				int extension;
> + 				NEXTOP(); /* skip over EXTENDED_ARG
> bytecode*/
> + 				extension = NEXTARG();
> + 				oparg = EXTEND_ARG(oparg, extension);
> + 			}
> + 		}
>   #ifdef DYNAMIC_EXECUTION_PROFILE
>   #ifdef DXPAIRS
>   		dxpairs[lastopcode][opcode]++;
> ...

I would like to see before-and-after timing tests on a few platforms:  this
approach adds a test+branch to every dynamic instance of an opcode with an
argument, and e.g. SET_LINENO and LOAD_FAST are by far the most frequently
executed opcodes (and both have arguments).

cautiously y'rs  - tim