Add back dart2js_aot rule which is used by golem.

Change-Id: I74b5acb7c3f67f4936bd2b6dfe0c46d20b82026d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/439020
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Siva Annamalai <asiva@google.com>
diff --git a/utils/compiler/BUILD.gn b/utils/compiler/BUILD.gn
index c8dfe53..f621419 100644
--- a/utils/compiler/BUILD.gn
+++ b/utils/compiler/BUILD.gn
@@ -75,6 +75,13 @@
   ]
 }
 
+aot_snapshot("dart2js_aot") {
+  deps = [ ":dart2js_create_snapshot_entry" ]
+
+  main_dart = "$target_gen_dir/dart2js.dart"
+  name = "dart2js_aot"
+}
+
 aot_snapshot("dart2js_sdk_aot") {
   deps = [ ":dart2js_create_snapshot_entry" ]