[infra] Translate _sources.gypi files to _sources.gni files

runtime/lib/collection_sources.gypi

Index: runtime/lib/collection_sources.gypi
diff --git a/runtime/lib/collection_sources.gypi b/runtime/lib/collection_sources.gypi
deleted file mode 100644
index 857698070ae53296a8f7d2ff2bd96f7818967e5c..0000000000000000000000000000000000000000
--- a/runtime/lib/collection_sources.gypi
+++ /dev/null
@@ -1,13 +0,0 @@
- # Copyright (c) 2013, 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.
-
-{
-  'sources': [
-    # collection_patch.dart needs to be the first dart file because it contains
-    # imports.
-    'collection_patch.dart',
-    'compact_hash.dart',
-    'linked_hash_map.cc',
-  ],
-}