anchor.diff:  
       member private tcImports.AttachDisposeAction action =
           CheckDisposed()
  -        disposeActions <- action :: disposeActions
  +        disposeActions.Add action
   
   #if !NO_EXTENSIONTYPING
       member private tcImports.AttachDisposeTypeProviderAction action =
           CheckDisposed()
  -        disposeTypeProviderActions <- action :: disposeTypeProviderActions
  +        disposeTypeProviderActions.Add action
   #endif
     
       // Note: the returned binary reader is associated with the tcImports, i.e. when the tcImports are closed 
  
positive.code:         knownUnresolved
          |> List.map (function UnresolvedAssemblyReference(file, originalReferences) -> file, originalReferences)
          |> List.iter reportAssemblyNotResolved
  
      override tcImports.Finalize () =
          dispose ()
          
      static member BuildNonFrameworkTcImports (ctok, tcConfigP: TcConfigProvider, tcGlobals: TcGlobals, baseTcImports, nonFrameworkReferences, knownUnresolved) = 
        cancellable {
  
negative.code:     let mutable dllTable: NameMap<ImportedBinary> = NameMap.empty
      let mutable ccuInfos: ImportedAssembly list = []
      let mutable ccuTable: NameMap<ImportedAssembly> = NameMap.empty
      let disposeActions = ResizeArray()
      let mutable disposed = false
      let mutable ilGlobalsOpt = ilGlobalsOpt
      let mutable tcGlobals = None
  #if !NO_EXTENSIONTYPING
      let disposeTypeProviderActions = ResizeArray()
      let mutable generatedTypeRoots = new System.Collections.Generic.Dictionary<ILTypeRef, int * ProviderGeneratedType>()
      let mutable tcImportsWeak = TcImportsWeakHack (WeakReference<_> this)
  #endif
  
      let disposal = new TcImportsSafeDisposal(disposeActions, disposeTypeProviderActions, compilationThread)
      
      let CheckDisposed() =
          if disposed then assert false
  
      let dispose () =
          CheckDisposed()
          (disposal :> IDisposable).Dispose()
  
      static let ccuHasType (ccu: CcuThunk) (nsname: string list) (tname: string) =
          let matchNameSpace (entityOpt: Entity option) n =
  