[gn] Fix precompile_tools=true

gn_dart_compile_exe.py wrapper stopped working because we rearranged
something in the prebuilt SDK. However we no longer need it because
we can ask `compile exe` itself to produce the depfile.

TEST=manually
R=kustermann@google.com

Change-Id: If5e64ede08b4e146a7bf033e7ef2d1809f40de1f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/435500
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>

utils/BUILD.gn

@@ -8,7 +8,7 @@ import("../sdk_args.gni")
 _dart_root = get_path_info("..", "abspath")
 
 template("aot_compile_using_prebuilt_sdk") {
-  action(target_name) {
+  prebuilt_dart_action(target_name) {
     forward_variables_from(invoker,
                            [
                              "deps",
@@ -17,31 +17,24 @@ template("aot_compile_using_prebuilt_sdk") {
                              "visibility",
                            ])
 
-    script = "$_dart_root/build/gn_dart_compile_exe.py"
-
     inputs = [
       invoker.entry_point,
       invoker.package_config,
     ]
-
     outputs = [ invoker.output ]
-
     depfile = invoker.output + ".d"
 
-    # TODO(vegorov): support RBE by using rewrapper script.
     args = [
-      "--dart-sdk",
-      rebase_path("$_dart_root/tools/sdks/dart-sdk", root_build_dir),
-      "--sdk-hash",
-      "$sdk_hash",
-      "--entry-point",
-      rebase_path(invoker.entry_point, root_build_dir),
-      "--output",
-      rebase_path(invoker.output, root_build_dir),
+      "compile",
+      "exe",
       "--packages",
       rebase_path(invoker.package_config, root_build_dir),
+      "-Dsdk_hash=$sdk_hash",
       "--depfile",
       rebase_path(depfile, root_build_dir),
+      "-o",
+      rebase_path(invoker.output, root_build_dir),
+      rebase_path(invoker.entry_point, root_build_dir),
     ]
   }
 }