Flatbuffers Merge commit '8cd6f0538a362ceefbcfcbf6c7b8b3f341d1fb41' into master

Upgrade flatbuffers to the latest.

Change-Id: I901787ac6fc5d7ce2c4019cc0d275de68086b4d8
diff --git a/third_party/flatbuffers/js/flexbuffers/bit-width.js b/third_party/flatbuffers/js/flexbuffers/bit-width.js
new file mode 100644
index 0000000..d0c5c05
--- /dev/null
+++ b/third_party/flatbuffers/js/flexbuffers/bit-width.js
@@ -0,0 +1,10 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.BitWidth = void 0;
+var BitWidth;
+(function (BitWidth) {
+    BitWidth[BitWidth["WIDTH8"] = 0] = "WIDTH8";
+    BitWidth[BitWidth["WIDTH16"] = 1] = "WIDTH16";
+    BitWidth[BitWidth["WIDTH32"] = 2] = "WIDTH32";
+    BitWidth[BitWidth["WIDTH64"] = 3] = "WIDTH64";
+})(BitWidth = exports.BitWidth || (exports.BitWidth = {}));