[pmc2c] compile-time expand pcc params and set the return result #1080

optimize pmc2c to emit static fill_params from compile-time known
params into the _call_object args array, ditto for the return values.
[pmc2c] fixup Chirags code a bit

fallback to old slow code with unknown arg adverbs.
fix indices and whitespace and more codingstd with Chirags code.
add helper function convert_pcc_sigtype for args and return sigs.
still fails t/pmc/class.t for missing method arity checks
[pmc2c] add method arity check - GH #1080

on method calls without optional args do one
arity check, with the new exception message:
  "wrong number of arguments: %d passed, %d expected"
Matching the old exception message too many/few would require
two run-time checks, which costs ~2% in parrot-bench.

fixes t/pmc/class.t
[pmc2c] fix optional arg handling for methods GH #1080

handle now also :optional and :opt_flag at compile-time,
not at run-time. (o and p arg adverbs)
Unprovided args get initialized with empty defaults.
With optional args, fall back to the two-fold old too many
and too few arguments checks, for backward compat. (about 2% slower)
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.