Fix another test broken by immutable tuples going away.

() made an immutable tuple pre-GLR if all the bits are immutable.
Though List itself is immutable, its elements don't have to be, so two
captures can no longer be the same object if they are constructed
separately. We have to use eqv instead of === now.

Author: niner

S02-types/capture.t

@@ -87,7 +87,7 @@ plan 29;
     my $capture2 = \(1,2,3);
     try { foo8 $capture2 };  # note: no |$args here
 
-    ok $capture1 === $capture2,
+    ok $capture1 eqv $capture2,
         "unflattened captures can be passed to subs";
 }