Properly initialize X::AdHoc objects used in tests

t/sum.t

@@ -137,7 +137,7 @@ my @d;
 #? rakudo skip 'feed through a slurpy arity function'
 #@d <== $h.partials <== (2,3);
 #is @d.join(""), "3942", "partials inserts values in a feed"
-is $h.partials(4,5,Failure.new(X::AdHoc.new()),6).map({.WHAT.gist}), '(Foo3) (Foo3) (Failure)', "partials stops iterating on Failure (Partial,Cooked).";
+is $h.partials(4,5,Failure.new(X::AdHoc.new(:payload<foo>)),6).map({.WHAT.gist}), '(Foo3) (Foo3) (Failure)', "partials stops iterating on Failure (Partial,Cooked).";
 
 class Foo3r does Sum::Partial does Sum does Sum::Marshal::Raw {
         has $.accum is rw = 0;
@@ -157,7 +157,7 @@ class Foo3r does Sum::Partial does Sum does Sum::Marshal::Raw {
 my Foo3r $hr .= new();
 
 # XXX do some tests of laziness of partials method
-is $hr.partials(4,5,Failure.new(X::AdHoc.new()),6).map({.WHAT.gist}), '(Foo3r) (Foo3r) (Failure)', "partials stops iterating on Failure (Partial,Raw).";
+is $hr.partials(4,5,Failure.new(X::AdHoc.new(:payload<foo>)),6).map({.WHAT.gist}), '(Foo3r) (Foo3r) (Failure)', "partials stops iterating on Failure (Partial,Raw).";
 
 lives-ok {
 class Foo4 does Sum::Partial does Sum does Sum::Marshal::Method[:atype(Str) :method<ords>] {