anchor.diff:              | P _ -> []
               | M m | C m -> m.FormalMethodTypars
               | V v -> v.Typars 
  -        tps |> List.map (fun tp -> FSharpGenericParameter(cenv,  tp)) |> List.toArray |> makeReadOnlyCollection
  +        tps |> List.map (fun tp -> FSharpGenericParameter(cenv,  tp)) |> makeReadOnlyCollection
   
       member x.FullType = 
           checkIsResolved()
  
positive.code: 
      member __.UnionCaseFields = 
          if isUnresolved() then makeReadOnlyCollection [] else
          v.UnionCase.RecdFields |> List.mapi (fun i _ ->  FSharpField(cenv,  FSharpFieldData.Union (v, i))) |> List.toArray |> makeReadOnlyCollection
  
      member __.ReturnType = 
          checkIsResolved()
  
negative.code: 
  namespace Microsoft.FSharp.Compiler.SourceCodeServices
  
  open System.Collections.Generic
  open Microsoft.FSharp.Compiler
  open Microsoft.FSharp.Compiler.AbstractIL.Internal.Library
  open Microsoft.FSharp.Compiler.AbstractIL.IL
  