C++: Privately import 'Node0ToString'.

Author: MathiasVP

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowPrivate.qll

@@ -6,7 +6,7 @@ private import semmle.code.cpp.ir.internal.IRCppLanguage
 private import SsaInternals as Ssa
 private import DataFlowImplCommon as DataFlowImplCommon
 private import codeql.util.Unit
-import Node0ToString
+private import Node0ToString
 
 cached
 private module Cached {

cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/DataFlowUtil.qll

@@ -15,6 +15,7 @@ private import ModelUtil
 private import SsaInternals as Ssa
 private import DataFlowImplCommon as DataFlowImplCommon
 private import codeql.util.Unit
+private import Node0ToString
 
 /**
  * The IR dataflow graph consists of the following nodes: