Support operator*/-> in new flatbuffers API

This was suggested during the initial reviews, and does seem to reduce a
fair amount of overhead.

Change-Id: Icb22106612c3a8430afa0b9dbe0a85f835e5b821
Signed-off-by: James Kuszmaul <james.kuszmaul@bluerivertech.com>
diff --git a/aos/flatbuffers/builder.h b/aos/flatbuffers/builder.h
index 6999649..75e0fe2 100644
--- a/aos/flatbuffers/builder.h
+++ b/aos/flatbuffers/builder.h
@@ -84,6 +84,8 @@
   // Returns the actual object for you to operate on and construct the
   // flatbuffer. Unlike AsFlatbufferSpan(), this will be stable.
   T *get() { return &flatbuffer_.t; }
+  T &operator*() { return *get(); }
+  T *operator->() { return get(); }
 
  private:
   size_t Alignment() const override { return flatbuffer_.t.Alignment(); }