Concat broken with BigInt ranges

[dlfivefifty]

julia> [1; 2; 1:BigInt(1000)]
ERROR: TypeError: in typeassert, expected Tuple{Vararg{Union{Int64, Tuple{Vararg{Int64, N}} where N}, N} where N}, got a value of type Tuple{Tuple{Int64}, Tuple{Int64}, Tuple{BigInt}}
Stacktrace:
 [1] _cat_t(::Val{1}, ::Type{BigInt}, ::Int64, ::Vararg{Any, N} where N)
   @ Base ./abstractarray.jl:1634
 [2] cat_t(::Type{BigInt}, ::Int64, ::Vararg{Any, N} where N; dims::Val{1})
   @ Base ./abstractarray.jl:1631
 [3] _cat(::Val{1}, ::Int64, ::Vararg{Any, N} where N)
   @ Base ./abstractarray.jl:1629
 [4] cat(::Int64, ::Vararg{Any, N} where N; dims::Val{1})
   @ Base ./abstractarray.jl:1768
 [5] vcat(::Int64, ::Int64, ::UnitRange{BigInt})
   @ Base ./abstractarray.jl:1697
 [6] top-level scope
   @ REPL[5]:1

I'm working on a redesign. See also #37741

[laborg]

This works since #37741 has landed

# tested on 1.7.1 and master
julia> [1; 2; 1:BigInt(1000)]
1002-element Vector{BigInt}:
    1
    2
    1
    ⋮
  998
  999
 1000