Cannot return byref after assigning to value from an array

Please provide a succinct description of the issue.

**Repro steps**

```fsharp
let f () =
let xs = Array.zeroCreate 128
let x = &xs.[0]
&x
```

**Expected behavior**

Compiles

**Actual behavior**

Errors on `&x`

**Known workarounds**

```fsharp
let g () =
let xs = Array.zeroCreate 128
&xs.[0]

let f () =
let x = &g ()
&x
```