Support structs in json_to_flatbuffer

Our JSON flatbuffer parsing code did not support structs properly.

Doing this enables easily defining lots of different layouts of
flatbuffers for more thoroughly testing flatbuffer-related changes (as
well as just making the JSON parsing more complete).

Change-Id: Ibfc7a149f9c8b314f6bbba70b4ca6b5857a8728b
Signed-off-by: James Kuszmaul <james.kuszmaul@bluerivertech.com>
diff --git a/aos/json_tokenizer.h b/aos/json_tokenizer.h
index 892c575..ab928f4 100644
--- a/aos/json_tokenizer.h
+++ b/aos/json_tokenizer.h
@@ -5,6 +5,7 @@
 #include <string_view>
 #include <vector>
 
+#include "absl/strings/numbers.h"
 #include "flatbuffers/util.h"
 
 namespace aos {
@@ -41,7 +42,7 @@
 
   // Parses the current field value as a long long.  Returns false if it failed
   // to parse.
-  bool FieldAsInt(long long *value);
+  bool FieldAsInt(absl::int128 *value);
   // Parses the current field value as a double.  Returns false if it failed
   // to parse.
   bool FieldAsDouble(double *value);