merge revision(s) r46775: [Backport #10016]

	* vm_insnhelper.c (vm_callee_setup_keyword_arg): adjust VM stack
	  pointer to get rid of overwriting splat arguments by arguments
	  for `to_hash` conversion.  [ruby-core:63593] [Bug #10016]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@47138 b2dd03c8-39d4-4d8f-98ff-823fe69b080e