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

build/sanitize-win-build-log.sed

Index: build/sanitize-win-build-log.sed
diff --git a/build/sanitize-win-build-log.sed b/build/sanitize-win-build-log.sed
new file mode 100644
index 0000000000000000000000000000000000000000..c18e664c83a052e5b09fc7f3442b1dd4c7546533
--- /dev/null
+++ b/build/sanitize-win-build-log.sed
@@ -0,0 +1,15 @@
+# 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.
+
+# Use this sed script to reduce a Windows build log into something
+# machine-parsable.
+
+# Drop uninformative lines.
+/The operation completed successfully\./d
+
+# Drop parallelization indicators on lines.
+s/^[0-9]+>//
+
+# Shorten bindings generation lines
+s/^.*"python".*idl_compiler\.py".*("[^"]+\.idl").*$/  idl_compiler \1/