GSOC#2 compile-time expand pcc params and set the return result

[rurban]

PCCMETHODs can be optimized to omit the run-time call to Parrot_pcc_fill_params_from_c_args(interp, _call_object, sig, &_self, args...);
and create the necessary C code to fill the params directly in pmc2c.
E.g. for "Pi" _self = VTABLE_get_pmc_keyed_int(interp, _call_object, 0); with _self being the first arg and 0 being the index for the first argument.

Same for assigning the RETURN result:
Parrot_pcc_set_call_from_c_args(interp, _call_object, rettype, result);
which only sets one argument, so a call set_call_from_varargs is not needed, just the type-specific part from set_call_from_varargs.
E.g. VTABLE_set_integer_keyed_int(interp, _call_object, 0, retvar);

Unfortunately we have to check the number of provided arguments at run-time: VTABLE_get_integer(interp, _call_object); and throw EXCEPTION_INVALID_OPERATION if too less or too many.
:optional and :opt_flag handling can be left to the old slow method or also expanded. (see rurban/pcc-opt-gh1080)
The flags flatten, lookahead, name and slurpy and multiple return values are rarely used and should be left to the old method. :constant should be expanded, but is not used yet.

This saves two unneccessary nested function calls, and one intermediate PMC creation just for holding the sig array and will lead to about 2-4% faster code with method calls. The arity check for the number of provided vs expected args is now the bottleneck.

[rurban]

Merged with commit 000a132
Merge: 9e15179 65f5def
Author: Reini Urban rurban@cpanel.net
Date: Tue Jul 1 15:30:26 2014 -0500

Merge branch 'rurban/pcc-opt-gh1080'

Second part of GSOC, but surprisingly with only minimal performance
impact on normal code (~0.5%). About 4-10% faster per method call.