Add a snapshot of flutter/engine/src/build to our sdk

build/win/importlibs/create_import_lib.gypi

Index: build/win/importlibs/create_import_lib.gypi
diff --git a/build/win/importlibs/create_import_lib.gypi b/build/win/importlibs/create_import_lib.gypi
new file mode 100644
index 0000000000000000000000000000000000000000..9cb0d345480e98dc55357655ca9dde0008ac1a0e
--- /dev/null
+++ b/build/win/importlibs/create_import_lib.gypi
@@ -0,0 +1,53 @@
+# Copyright (c) 2012 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# This file is meant to be included into a target to provide a rule
+# to create import libraries from an import description file in a consistent
+# manner.
+#
+# To use this, create a gyp target with the following form:
+# {
+#   'target_name': 'my_proto_lib',
+#   'type': 'none',
+#   'sources': [
+#     'foo.imports',
+#     'bar.imports',
+#   ],
+#   'variables': {
+#     # Optional, see below: 'proto_in_dir': '.'
+#     'create_importlib': 'path-to-script',
+#     'lib_dir': 'path-to-output-directory',
+#   },
+#   'includes': ['path/to/this/gypi/file'],
+# }
+#
+# This will generate import libraries named 'foo.lib' and 'bar.lib' in the
+# specified lib directory.
+
+{
+  'variables': {
+    'create_importlib': '<(DEPTH)/build/win/importlibs/create_importlib_win.py',
+    'lib_dir': '<(PRODUCT_DIR)/lib',
+  },
+  'rules': [
+    {
+      'rule_name': 'create_import_lib',
+      'extension': 'imports',
+      'inputs': [
+        '<(create_importlib)',
+      ],
+      'outputs': [
+        '<(lib_dir)/<(RULE_INPUT_ROOT).lib',
+      ],
+      'action': [
+        'python',
+        '<(create_importlib)',
+        '--output-file', '<@(_outputs)',
+        '<(RULE_INPUT_PATH)',
+      ],
+      'message': 'Generating import library from <(RULE_INPUT_PATH)',
+      'process_outputs_as_sources': 0,
+    },
+  ],
+}