merge revision(s) 45320,45321: [Backport #9622]

	* vm_insnhelper.c (vm_callee_setup_arg): turn a macro into an
	  inline function.

	* vm_insnhelper.c (vm_callee_setup_arg): disable fastpath if splat
	  argument, since argc may differ for each calls.
	  [ruby-core:61422] [Bug #9622]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@45748 b2dd03c8-39d4-4d8f-98ff-823fe69b080e