Incorrect type inference when destructing struct into named tuple

[rben01]

Sample code:

struct A
    x::Int
end

struct S
    a::A
end

function f()
    s = S(A(1))
    (; a) = s
    println(a.x)  # !! Missing reference: x
    println(a.a)  # !! This is marked ok, but will fail at runtime
    return nothing
end

Julia allows tuple destructing structs into a named tuple whose fields get assigned to the fields of the struct. However, the Julia extension’s type inference incorrectly infers the type of the resulting variables. In the above example, (; a) = s leads to the extension assuming a has type S, not A. This leads it to think that a doesn't have a field x when it does, and that a does have a field a when it doesn't. Type inference should be updated to correctly unpack the fields of the struct into the named tuple.