Missing attributes information on `setter` of a property (in `FSharpMemberOrFunctionOrValue` type)

Hello,

I am not sure how to report this bug because this is related to the internals of F# Compiler itself, and happening inside of Fable transformation.

In Fable, we want to erase types and properties decorated with `[]`.

For example, this code should emit nothing.

```fs
[]
type internal LanguageInjectionAttribute() =
inherit Attribute()

[]
member val Prefix = "" with get, set
```

However, currently it does not seems possible to do it for the `setter` because it is missing the `[]` attribute information:


Please tell me, if I can do anything to reword my issue or help you identify the cause of this problem.