implement lufact(A::HermOrSym)

[fredrikekre]

This also fixed the following:

julia> A = rand(3, 3); S = Symmetric(A'A); D = Diagonal(rand(3));

julia> S\D
3×3 Array{Float64,2}:
  4.47548    0.58589  -2.70101
  0.799888   2.49059  -1.74015
 -4.00037   -1.88777   3.61472

julia> S\S
3×3 Array{Float64,2}:
 1.0  0.0  0.0
 0.0  1.0  0.0
 0.0  0.0  1.0

but I am not sure this is the correct fix for that so I have not yet included tests for that. The other fix would be to relax the method definition here. Regardless, I think it could be useful to have lufact work for Symmetric/Hermitian. Thoughts?

[fredrikekre]

Thanks, could you comment on my question in the OP @andreasnoack ? :)

[andreasnoack]

I think it would be fine to relax the other method as well. Would it introduce any ambiguities?

[fredrikekre]

See #22561