* rewrite method/block parameter fitting logic to optimize
  keyword arguments/parameters and a splat argument.
  [Feature #10440] (Details are described in this ticket)
  Most of complex part is moved to vm_args.c.
  Now, ISeq#to_a does not catch up new instruction format.
* vm_core.h: change iseq data structures.
  * introduce rb_call_info_kw_arg_t to represent keyword arguments.
  * add rb_call_info_t::kw_arg.
  * rename rb_iseq_t::arg_post_len to rb_iseq_t::arg_post_num.
  * rename rb_iseq_t::arg_keywords to arg_keyword_num.
  * rename rb_iseq_t::arg_keyword to rb_iseq_t::arg_keyword_bits.
    to represent keyword bitmap parameter index.
    This bitmap parameter shows that which keyword parameters are given
    or not given (0 for given).
    It is refered by `checkkeyword' instruction described bellow.
  * rename rb_iseq_t::arg_keyword_check to rb_iseq_t::arg_keyword_rest
    to represent keyword rest parameter index.
  * add rb_iseq_t::arg_keyword_default_values to represent default
    keyword values.
  * rename VM_CALL_ARGS_SKIP_SETUP to VM_CALL_ARGS_SIMPLE
    to represent
      (ci->flag & (SPLAT|BLOCKARG)) &&
      ci->blockiseq == NULL &&
      ci->kw_arg == NULL.
* vm_insnhelper.c, vm_args.c: rewrite with refactoring.
  * rewrite splat argument code.
  * rewrite keyword arguments/parameters code.
  * merge method and block parameter fitting code into one code base.
* vm.c, vm_eval.c: catch up these changes.
* compile.c (new_callinfo): callinfo requires kw_arg parameter.
* compile.c (compile_array_): check the last argument Hash object or
  not. If Hash object and all keys are Symbol literals, they are
  compiled to keyword arguments.
* insns.def (checkkeyword): add new instruction.
  This instruction check the availability of corresponding keyword.
  For example, a method "def foo k1: 'v1'; end" is cimpiled to the
  following instructions.
    0000 checkkeyword     2, 0  # check k1 is given.
    0003 branchif         9     # if given, jump to address #9
    0005 putstring        "v1"
    0007 setlocal_OP__WC__0 3   # k1 = 'v1'
    0009 trace            8
    0011 putnil
    0012 trace            16
    0014 leave
* insns.def (opt_send_simple): removed and add new instruction
  "opt_send_without_block".
* parse.y (new_args_tail_gen): reorder variables.
  Before this patch, a method "def foo(k1: 1, kr1:, k2: 2, **krest, &b)"
  has parameter variables "k1, kr1, k2, &b, internal_id, krest",
  but this patch reorders to "kr1, k1, k2, internal_id, krest, &b".
  (locate a block variable at last)
* parse.y (vtable_pop): added.
  This function remove latest `n' variables from vtable.
* iseq.c: catch up iseq data changes.
* proc.c: ditto.
* class.c (keyword_error): export as rb_keyword_error().
* common.mk: depend vm_args.c for vm.o.
* hash.c (rb_hash_has_key): export.
* internal.h: ditto.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48239 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* properties.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48240 b2dd03c8-39d4-4d8f-98ff-823fe69b080e