Make get_label_info take into account the toolchain for target_gen_dir

tools/gn/ninja_utils.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "tools/gn/ninja_utils.h"
 
 #include "tools/gn/filesystem_utils.h"
 #include "tools/gn/settings.h"
 #include "tools/gn/target.h"
 
 SourceFile GetNinjaFileForTarget(const Target* target) {
-  return SourceFile(GetTargetOutputDir(target).value() +
-                    target->label().name() + ".ninja");
+  return SourceFile(
+      GetBuildDirForTargetAsSourceDir(target, BuildDirType::OBJ).value() +
+      target->label().name() + ".ninja");
 }
 
 SourceFile GetNinjaFileForToolchain(const Settings* settings) {
-  return SourceFile(GetToolchainOutputDir(settings).value() +
-                    "toolchain.ninja");
+  return SourceFile(GetBuildDirAsSourceDir(
+      BuildDirContext(settings), BuildDirType::TOOLCHAIN_ROOT).value() +
+      "toolchain.ninja");
 }
 
 std::string GetNinjaRulePrefixForToolchain(const Settings* settings) {
   // Don't prefix the default toolchain so it looks prettier, prefix everything
   // else.
   if (settings->is_default())
     return std::string();  // Default toolchain has no prefix.
   return settings->toolchain_label().name() + "_";
 }