fix repl completions on unions and Any

[KristofferC]

Fix #23284

[KristofferC]

The circleci test failure is weird:

Error in testset statistics:
Error During Test
  Got an exception of type LoadError outside of a @test
  LoadError: return type RowVector{Float64,Array{Float64,1}} does not match inferred return type Any
  Stacktrace:
   [1] abstract_call(::Any, ::Tuple{}, ::Array{Any,1}, ::Array{Any,1}, ::Core.Inference.InferenceState) at ./inference.jl:2285
   [2] finddoc(::Base.Docs.##9#11{String,Bool}, ::Expr) at ./docs/Docs.jl:632
  while loading /tmp/julia/share/julia/test/statistics.jl, in expression starting on line 177
ERROR: LoadError: Test run finished with errors
while loading /tmp/julia/share/julia/test/runtests.jl, in expression starting on line 29

Dont think it is related to this PR?

[fredrikekre]

Same error in #23341

[KristofferC]

Anyone feel like looking over this?

[StefanKarpinski]

What does it need? Does it pass tests at this point or no?

[KristofferC]

It needs review.

[StefanKarpinski]

It looks reasonable to me, but I don't really understand what it's doing, so if it fixes the problem, passes tests and doesn't seem to break things, then we can just merge it. Otherwise, you'll need to propose someone who understands this code to review it.

[rfourquet]

A bit late, but LGTM, thanks!