// addgostring adds str, as a Go string value, to s. symname is the name of the
// symbol used to define the string data and must be unique per linked object.
func addgostring(ctxt *Link, ldr *loader.Loader, s *loader.SymbolBuilder, symname, str string) {
	sdata := ldr.CreateSymForUpdate(symname, 0)
	if sdata.Type() != sym.Sxxx {
		ctxt.Errorf(s.Sym(), "duplicate symname in addgostring: %s", symname)
	}
	sdata.SetLocal(true)

      For example, this would transform

      "tf_saved_model.global_tensor"() { sym_name = "v" ... }
      func @f(%arg0 {tf_saved_model.bound_input = @v}) {
        %1 = "tf.ReadVariableOp"(%arg0)
        ...
      }

      to

      func @f(%arg0 {tf_saved_model.bound_input = @v}) {
        %0 = "tf.VarHandleOp"(sym_name = "v")
        %1 = "tf.ReadVariableOp"(%0)
        ...
      }