Adds produce refs #1731

Author: JJ

doc/Type/Any.pod6

@@ -874,6 +874,23 @@ L«C<List.classify>|/type/List#routine_classify» on it.
 
 =head2 method produce
 
+Defined as:
+
+    multi method produce(Any:U: & --> Nil)
+    multi method produce(Any:D: &with)
+    multi sub produce (&with, +list)
+
+This is similar to L<C<reduce>|/routine/reduce#(List)_routine_reduce>, but
+returns a list with the accumulated values instead of a single result.
+
+=for code
+<10 5 3>.reduce( &[*] ).say ; # OUTPUT: «150␤»
+<10 5 3>.produce( &[*] ).say; # OUTPUT: «(10 50 150)␤»
+
+The last element of the produced list would be the output produced by the
+C<.reduce> method.
+
+If it's a class, it will simply return Nil.
 
 =head2 method pairs