Change broken native/where dispatch hang test

The test tests circular hang does not occur, but relied on a buggy
behaviour that is now fixed[^1]. Fix the test by checking for hangs
using a different test routine.

Explanation why old behaviour was a bug:
https://irclog.perlgeek.de/perl6-dev/2016-10-25#i_13462673
https://rt.perl.org/Ticket/Display.html?id=129844#txn-1433016

[1] rakudo/rakudo@ccfa5e51a21f5a613ecb0cf

S06-multi/type-based.t

@@ -226,7 +226,8 @@ is(mmd(1..3), 2, 'Slurpy MMD to listop via list');
     # This once wrongly reported a multi-dispatch circularity.
     multi rt107638(int $a) { 'ok' }      #OK not used
     multi rt107638(Str $a where 1) { }   #OK not used
-    ok rt107638(1), 'native types and where clauses do not cause spurious circularities';
+    throws-like { rt107638(1) }, X::Multi::NoMatch,
+        'native types and where clauses do not cause spurious circularities';
 }
 
 # Coercion types introduce two candidates