These missing dependencies will cause a violation of "gn check" in a future version of gn.

runtime/bin/BUILD.gn

 # Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 
 declare_args() {
   dart_io_support = false
 }
 
 
@@ skipping 125 matching lines @@
 
   defines = [
     "DART_SHARED_LIB",
   ]
 }
 
 
 executable("gen_snapshot") {
   configs += ["..:dart_config"]
   deps = [
+    ":generate_builtin_cc_file",
+    ":generate_io_cc_file",
+    ":generate_io_patch_cc_file",
+    ":libdart_builtin",
     ":libdart_nosnapshot",
-    ":libdart_builtin",
   ]
 
   sources = [
     "address_sanitizer.cc",
     "gen_snapshot.cc",
     # Very limited native resolver provided.
     "builtin_common.cc",
     "builtin_gen_snapshot.cc",
     "builtin.cc",
     "builtin.h",
@@ skipping 74 matching lines @@
     "log_macos.cc",
     "log_win.cc",
     "log.h",
   ]
 
   include_dirs = [
     "..",
     "//third_party"
   ]
 }