Make get_label_info take into account the toolchain for target_gen_dir

tools/gn/ninja_utils.cc

Index: tools/gn/ninja_utils.cc
diff --git a/tools/gn/ninja_utils.cc b/tools/gn/ninja_utils.cc
index 60d4d3643842cd7594d678cb79daf3f99db85e32..9e9039220af65499b834f0c9bf450e34077a41dc 100644
--- a/tools/gn/ninja_utils.cc
+++ b/tools/gn/ninja_utils.cc
@@ -9,13 +9,15 @@
 #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) {