Symbols API: FSharpEntity.IsByRef is false for byref`1

[auduchinok]

I've encountered this issue in the type of return parameter of ~& in prim-types.fs in FSharp.Core project by getting property mfv.ReturnParameter.Type.TypeDefinition.IsByRef.
The mfv symbol was taken from GetAllUsesOfAllSymbolsInFile and I think the underlying issue may be in FSharpSymbol.Create, which I'm going to look into.
https://github.com/Microsoft/visualfsharp/blob/83208f8cb02e8d6d56757e45cd73545524180644/src/fsharp/FSharp.Core/prim-types.fs#L540-L543