Try to fix balanced tree test

not quite right, but at least it doesn't abort anymore

integration/99problems-51-to-60.t

@@ -59,27 +59,27 @@ plan 37;
                 my $k = ($n - 1) div 2;
                 for cbal-tree($k) -> $a {
                     for cbal-tree($k) -> $b {
-                        take ['x', $a, $b];
+                        take ['x', $a, $b],;
                     }
                 }
             } else {
                 my $k = $n div 2;
                 for cbal-tree($k) -> $a {
                     for cbal-tree($k - 1) -> $b {
-                        take ['x', $a, $b];
+                        take ['x', $a, $b],;
                     }
                 }
                 for cbal-tree($k - 1) -> $a {
                     for cbal-tree($k) -> $b {
-                        take ['x', $a, $b];
+                        take ['x', $a, $b],;
                     }
                 }
             }
         }
     }
 
     is-deeply [ cbal-tree(1) ],
-       [['x', Any, Any]],
+       [['x', Any, Any],],
        'built a balanced binary tree with 1 item';
 
     is-deeply [ cbal-tree(2) ], 
@@ -243,17 +243,17 @@ plan 37;
     }
 
     sub hbal-tree(Int $n) {
-        return Mu if $n == 0;
-        return ['x', Mu, Mu] if $n == 1;
+        return Any if $n == 0;
+        return(['x', Any, Any],) if $n == 1;
         gather {
             for hbal-tree($n - 1) -> $a {
                 for hbal-tree($n - 1) -> $b {
-                    take ['x', $a, $b];
+                    take ['x', $a, $b],;
                 }
                 for hbal-tree($n - 2) -> $b {
                     if is-hbal(['x', $a, $b]) {
-                        take ['x', $a, $b];
-                        take ['x', $b, $a];
+                        take ['x', $a, $b],;
+                        take ['x', $b, $a],;
                     }
                 }
             }