IteratorSize for infinite AbstractFill

[jishnub]

Implement IteratorSize by looping over the types of the axes, and checking if any of them is infinite. With this and JuliaArrays/InfiniteArrays.jl#105, we obtain

julia> x = Ones(1:∞);

julia> Base.IteratorSize(x)
Base.IsInfinite()

julia> s = Iterators.Stateful(x)
Base.Iterators.Stateful{Ones{Int64, 1, Tuple{InfiniteArrays.OneToInf{Int64}}}, Tuple{Int64, Tuple{Int64, Int64}}, Int64}(Ones(ℵ₀), (1, (1, 1)), -1)

julia> first(s,2)
2-element Vector{Int64}:
 1
 1

[codecov]

Codecov Report

Merging #205 (dff7722) into master (617be46) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #205      +/-   ##
==========================================
+ Coverage   97.89%   97.92%   +0.03%     
==========================================
  Files           4        4              
  Lines         665      676      +11     
==========================================
+ Hits          651      662      +11     
  Misses         14       14              

Impacted Files	Coverage Δ
src/FillArrays.jl	97.45% <100.00%> (+0.08%)	⬆️

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more