[perl #126708] Grammar.parse does not ignore unknown named args

[jn...@jnthn.net via RT]

On Sun Nov 22 10:58:57 2015, b...@abrij.org wrote:
> 
> This is a regression since star09 which make Grammar more tedious to
> subclass.
> 
> (01:52:42 PM) skids: m: grammar foo {  rule TOP { . } };
> foo.parse("foo",:subclass_arg_to_ignore)
> (01:53:02 PM) camelia: rakudo-moar : OUTPUT«Unexpected named parameter
> 'subclass_arg_to_ignore' passed␤  in block <unit> at
> /tmp/cUwyy7Hppz:1␤␤»
> (01:53:12 PM) skids: star: grammar foo {  rule TOP { . } };
> foo.parse("foo",:subclass_arg_to_ignore)
> (01:53:12 PM) camelia: star-m 2015.09: ( no output )
> (01:53:34 PM) skids: That was breaking Grammar::BNF but I worked
> around it.

Fixed, and test coverage added to S12-class/interface-consistency.t.