Type capture in parametarization NYI

[zoffixznet]

User wanting this: https://irclog.perlgeek.de/perl6/2018-01-10#i_15673129

<Zoffix_> m: -> Array[::T] \a, Array[T] \b {}(Array[Int], Array[Int])
<camelia> rakudo-moar f02606cea: OUTPUT: «===SORRY!=== Error while compiling <tmp>␤No such symbol 'T'␤at <tmp>:1␤------> -> Array[::T⏏] \a, Array[T] \b {}(Array[Int], Array[I␤»

Possible workaround:

11:13 | Zoffix | m: -> ::T \a where Array[T.of], \b where Array[T.of] {}(Array[Int], Array[Int])
-- | -- | --
11:13 | camelia | rakudo-moar f02606cea: ( no output )
11:13 | Zoffix | m: -> ::T \a where Array[T.of], \b where Array[T.of] {}(Array[Int], Array[Num])
11:13 | camelia | rakudo-moar f02606cea: OUTPUT: «Constraint type check failed in binding to parameter 'b'; expected anonymous constraint to be met but got Array[Num] (Array[Num])␤  in block <unit> at <tmp> line 1␤␤»