More fixes for the Windows GN build.

courgette/BUILD.gn

Index: courgette/BUILD.gn
diff --git a/courgette/BUILD.gn b/courgette/BUILD.gn
index 371085447ca59779c3b832eb304ad6424405cd82..f8514e1975b232ce39699cf387a2686b07aa6efe 100644
--- a/courgette/BUILD.gn
+++ b/courgette/BUILD.gn
@@ -129,14 +129,16 @@ if (!is_ios) {
       # Make sure that we have a copy of courgette64.exe in the root out
       # directory.
       copy("copy_courgette_binaries") {
+        courgette64_label = ":courgette(//build/toolchain/win:x64)"
+        courgette64_out_dir = get_label_info(courgette64_label, "root_out_dir")
         sources = [
-          "$root_out_dir/x64/courgette64.exe",
+          "$courgette64_out_dir/courgette64.exe",
         ]
         outputs = [
-          "$root_out_dir/courgette64.exe",
+          "$root_out_dir/{{source_file_part}}",
         ]
         deps = [
-          ":courgette(//build/toolchain/win:x64)",
+          courgette64_label,
         ]
       }
     }