Specialize ∘ on type arguments?

[jw3126]

The following does not infer:

julia> f(itr) = map(Int∘sign, itr)
f (generic function with 2 methods)

julia> f((1,))
(1,)

julia> @code_warntype f((1,))
Variables
  #self#::Core.Compiler.Const(f, false)
  itr::Tuple{Int64}

Body::Tuple{Any}
1 ─ %1 = (Main.Int ∘ Main.sign)::Core.Compiler.Const(Base.var"#56#57"{DataType,typeof(sign)}(Int64, sign), false)
│   %2 = Main.map(%1, itr)::Tuple{Any}
└──      return %2

This occured here.

[tkf]

This is because closures capture types as DataTypes #23618 (comment)

It's easy to "fix" this for ∘ but it'd be great if it can be fixed for all closures.

[jw3126]

Ok I close this as it is a dup of #23618