anchor.diff:              | "skip" -> icall "slice" (i.args.Tail.Head, [i.args.Head])
               | "copy" -> icall "slice" (i.args.Head, [])
               | "getSubArray" | "fill" ->
  -                ccall com i "Array" i.methodName i.args |> Some
  +                ccall i "Array" i.methodName i.args |> Some
               | "truncate" ->
                   // Array.truncate count array
                   emit i "$1.slice(0, $0)" i.args |> Some
  
positive.code: 
      let bigint com (i: Fable.ApplyInfo) =
          match i.callee, i.methodName with
          | Some callee, meth -> icall com i meth |> Some
          | None, ".ctor" ->
              match i.args with
              | [Type (Fable.ExtendedNumber (Int64|UInt64))] -> ccall com i "BigInt" "fromInt64" i.args
              | [_] -> ccall com i "BigInt" "fromInt32" i.args
              | _ ->
                  CoreLibCall("BigInt", None, true, i.args)
                  |> makeCall i.range i.returnType
  
negative.code:         | Some callee -> callee::args
          | None -> args
  
      let icall (i: Fable.ApplyInfo) meth =
          let c, args = instanceArgs i.callee i.args
          InstanceCall(c, meth, args)
          |> makeCall i.range i.returnType
  
      let ccall (i: Fable.ApplyInfo) cmod meth args =
          CoreLibCall(cmod, Some meth, false, args)
          |> makeCall i.range i.returnType
  
      let ccall_ r t cmod meth args =
          CoreLibCall(cmod, Some meth, false, args)
          |> makeCall r t
  
      let emit (i: Fable.ApplyInfo) emit args =
          makeEmit i.range i.returnType args emit
  