merge revision(s) 40992: [Backport #8040]

	* vm_insnhelper.c (vm_callee_setup_keyword_arg,
	  vm_callee_setup_arg_complex): consider a hash argument for keyword
	  only when the number of arguments is more than the expected
	  mandatory parameters.  [ruby-core:53199] [ruby-trunk - Bug #8040]

	* test/ruby/test_keyword.rb: update a test for above.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@41063 b2dd03c8-39d4-4d8f-98ff-823fe69b080e