Add missing dependency in the rule which generates io_gen.cc

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
 
   # TODO(zra, jamesr): Remove this check once we start building boringssl for
   # the fuchsia port.
@@ skipping 35 matching lines @@
 
 template("gen_library_src_path") {
   assert(defined(invoker.sources), "Need sources in $target_name")
   assert(defined(invoker.output), "Need output in $target_name")
   action(target_name) {
     visibility = [ ":*" ]  # Only targets in this file can see this.
     script = "../tools/gen_library_src_paths.py"
     inputs = [
       "../tools/gen_library_src_paths.py",
       "builtin_in.cc",
-    ]
+    ] + invoker.sources

[jsimmons1, 2016/09/01 00:08:34]

Other actions in this file that pass a list of sources may have the same issue
(e.g. gen_resources_cc)

[siva, 2016/09/01 17:13:23]

I believe the rule for gen_resources_cc is ok as adds stuff from sources to the
dependencies.

     outputs = [ invoker.output, ]
     name = invoker.name
     kind = invoker.kind
     args = [
       "--output", rebase_path(invoker.output, root_build_dir),
       "--input_cc", rebase_path("builtin_in.cc", root_build_dir),
       "--include", "bin/builtin.h",
       "--var_name", "dart::bin::Builtin::${name}_${kind}_paths_",
       "--library_name", "dart:${name}",] +
       rebase_path(invoker.sources, root_build_dir)
@@ skipping 499 matching lines @@
     sources = [
       "run_vm_tests_fuchsia.cc"
     ]
     libs = [
       "launchpad",
       "magenta",
       "runtime",
     ]
   }
 }  # defined(is_fuchsia) && is_fuchsia