:U parametarized@,%,& parameters are incorrectly parametarized

[zoffixznet]

If you parametarize with a :D constraint, everything is peachy:

17:49 | Zoffix | m: -> Int:D @v { @v[^3] }(my Int:D @)
-- | -- | --
17:49 | camelia | rakudo-moar c9432c207: ( no output )

But if you use :U instead, then it appears as if the :U is applied to the constraint offered by the sigil (Positional/Associative/Callable) instead of the value it's parametarized with:

17:49 | Zoffix | m: -> Int:U @v { @v[^3] }(my Int:U @)
17:49 | camelia | rakudo-moar  c9432c207: OUTPUT: «Parameter '@v' of routine '<anon>' must be a  type object of type 'Positional[Int]', not an object instance of type  'Array[Int:U]'. Did you forget a 'multi'?␤ in block <unit> at  <tmp> line 1␤␤»
1352    @Zoffix │ m: my $b := -> Int:U @v { @v[^3] }; my \a := $b.signature.params.head.type; dd $b(a)                                                                 │
1352   +camelia │ rakudo-moar c9432c207: OUTPUT: «(Any, Any, Any)␤»


1353    @Zoffix │ m: -> Int:U %v { %v<a b c> }(my Int:U %)                                                                                                             │
1353   +camelia │ rakudo-moar c9432c207: OUTPUT: «Parameter '%v' of routine '<anon>' must be a type object of type 'Associative[Int]', not an object instance of type  │
                │ 'Hash[Int:U]'.  Did you forget a 'multi'?␤  in block <unit> at <tmp> line 1␤␤»


1354    @Zoffix │ m: -> Int:U &v { }(sub (--> Int:U) {})                                                                                                               │
1354   +camelia │ rakudo-moar c9432c207: OUTPUT: «Parameter '&v' of routine '<anon>' must be a type object of type 'Callable[Int]', not an object instance of type     │
                │ 'Sub+{Callable[Int:U]}'.  Did you forget a 'multi'?␤  in block <unit> at <tmp> line 1␤␤»

[zoffixznet]

There are some fudged tests in Raku/roast@8c8e8f55bb#diff-d442fea62726a360de696ce38077fcebR159 that may be sufficient to cover this bug.

[jnthn]

I wonder if it's accidentally somehow distributing the :U across both, and with the :D we just don't notice.