move Hash.ACCEPTS to the setting, add more variants

Actually I'm not fully convinced that this is right approach because I don't
understand the magic with hash_ACCEPTS that the anonymous sub in
src/classes/Hash.pir:32-41 does, but the spectest didn't throw up any black
smoke.

src/classes/Hash.pir

@@ -25,7 +25,7 @@ src/classes/Hash.pir - Perl 6 Hash class and related functions
 =cut
 
 .namespace ['Perl6Hash']
-.sub 'ACCEPTS' :method :subid('hash_ACCEPTS')
+.sub '' :method :subid('hash_ACCEPTS')
     .param pmc topic
     .tailcall self.'contains'(topic)
 .end

src/setting/Hash.pm

@@ -1,4 +1,17 @@
 class Hash is also {
+
+    multi method ACCEPTS(Regex $topic) {
+        any(@.keys) ~~ $topic;
+    }
+
+    multi method ACCEPTS(%topic) {
+        @.keys.sort eqv %topic.keys.sort;
+    }
+
+    multi method ACCEPTS($topic) {
+        $.contains($topic)
+    }
+
     multi method invert () is export {
         gather { 
             for @.pairs {