It seems converting a Q matrix to a Float Matrix takes high-degree polynomial time at best.

Is this a bug? If so, is there any way to work around it? I don’t remember having this problem on earlier versions (I am using 1.01). Granted my laptop is pretty slow, but this is worse than matrix inversion, so the performance doesn’t make a lot of sense to me.

```
using LinearAlgebra
function mwe()
local Q::Matrix{Float64}
X = rand(200,13)
f = qr(X)
@time Q = Matrix{Float64}(f.Q)
X = rand(400,13)
f = qr(X)
@time Q = Matrix{Float64}(f.Q)
X = rand(600,13)
f = qr(X)
@time Q = Matrix{Float64}(f.Q)
X = rand(800,13)
f = qr(X)
@time Q = Matrix{Float64}(f.Q)
end
mwe()
```

Output:

0.260873 seconds (120.00 k allocations: 145.569 MiB, 1.49% gc time)

2.115116 seconds (480.00 k allocations: 1.022 GiB, 3.70% gc time)

6.812497 seconds (1.08 M allocations: 3.372 GiB, 4.46% gc time)

15.563167 seconds (1.92 M allocations: 7.901 GiB, 3.08% gc time)