reduce(...; dims=...) doesn't check for invalid dims

[stevengj]

It seems like this should throw an exception:

julia> reduce(max, rand(3,4), dims=42)
3×4 Matrix{Float64}:
 0.27254   0.151595  0.800565  0.415303
 0.230914  0.546007  0.135317  0.107762
 0.701839  0.769241  0.875562  0.0847975

and probably also this:

julia> reduce(max, rand(3,4), dims=(1,2,2,2,2))
1×1 Matrix{Float64}:
 0.8197478258634205

(I noticed this in connection with #37367, which does check its dims argument.)

[rohanblueboybaijal]

Hi!
Is anyone working on this issue?
Would an error message suffice? And if so, should I be making changes in reduce.jl?