[Flight] Add support BigInt support (#26479)

## Summary

Adds support for sending `BigInt` to Flight and Flight Reply

## How did you test this change?

- added tests

DiffTrain build for [fd0511c](fd0511c)

Author: eps1lon

compiled/facebook-www/REVISION

@@ -1 +1 @@
-85de6fde515148babd36eae2b7384ad8e62b732a
+fd0511c728e186905b7f0e71f072b4b247d6f29f

compiled/facebook-www/ReactFlightDOMRelayClient-dev.classic.js

@@ -564,6 +564,11 @@ function parseModelString(response, parentObject, key, value) {
         return undefined;
       }
 
+      case "n": {
+        // BigInt
+        return BigInt(value.substring(2));
+      }
+
       default: {
         // We assume that anything else is a reference ID.
         var _id3 = parseInt(value.substring(1), 16);

compiled/facebook-www/ReactFlightDOMRelayClient-dev.modern.js

@@ -564,6 +564,11 @@ function parseModelString(response, parentObject, key, value) {
         return undefined;
       }
 
+      case "n": {
+        // BigInt
+        return BigInt(value.substring(2));
+      }
+
       default: {
         // We assume that anything else is a reference ID.
         var _id3 = parseInt(value.substring(1), 16);

compiled/facebook-www/ReactFlightDOMRelayClient-prod.classic.js

@@ -287,6 +287,8 @@ function parseModelString(response, parentObject, key, value) {
         }
       case "u":
         return;
+      case "n":
+        return BigInt(value.substring(2));
       default:
         value = parseInt(value.substring(1), 16);
         response = getChunk(response, value);

compiled/facebook-www/ReactFlightDOMRelayClient-prod.modern.js

@@ -287,6 +287,8 @@ function parseModelString(response, parentObject, key, value) {
         }
       case "u":
         return;
+      case "n":
+        return BigInt(value.substring(2));
       default:
         value = parseInt(value.substring(1), 16);
         response = getChunk(response, value);

compiled/facebook-www/ReactFlightDOMRelayServer-dev.classic.js

@@ -1771,6 +1771,10 @@ function serializeUndefined() {
   return "$undefined";
 }
 
+function serializeBigInt(n) {
+  return "$n" + n.toString(10);
+}
+
 function serializeClientReference(request, parent, key, clientReference) {
   var clientReferenceKey = getClientReferenceKey(clientReference);
   var writtenClientReferences = request.writtenClientReferences;
@@ -2110,12 +2114,7 @@ function resolveModelToJSON(request, parent, key, value) {
   }
 
   if (typeof value === "bigint") {
-    throw new Error(
-      "BigInt (" +
-        value +
-        ") is not yet supported in Client Component props." +
-        describeObjectForErrorMessage(parent, key)
-    );
+    return serializeBigInt(value);
   }
 
   throw new Error(

compiled/facebook-www/ReactFlightDOMRelayServer-dev.modern.js

@@ -1771,6 +1771,10 @@ function serializeUndefined() {
   return "$undefined";
 }
 
+function serializeBigInt(n) {
+  return "$n" + n.toString(10);
+}
+
 function serializeClientReference(request, parent, key, clientReference) {
   var clientReferenceKey = getClientReferenceKey(clientReference);
   var writtenClientReferences = request.writtenClientReferences;
@@ -2110,12 +2114,7 @@ function resolveModelToJSON(request, parent, key, value) {
   }
 
   if (typeof value === "bigint") {
-    throw new Error(
-      "BigInt (" +
-        value +
-        ") is not yet supported in Client Component props." +
-        describeObjectForErrorMessage(parent, key)
-    );
+    return serializeBigInt(value);
   }
 
   throw new Error(

compiled/facebook-www/ReactFlightDOMRelayServer-prod.classic.js

@@ -909,13 +909,7 @@ function resolveModelToJSON(request, parent, key, value) {
     element.set(value, key);
     return "$" + key.toString(16);
   }
-  if ("bigint" === typeof value)
-    throw Error(
-      "BigInt (" +
-        value +
-        ") is not yet supported in Client Component props." +
-        describeObjectForErrorMessage(parent, key)
-    );
+  if ("bigint" === typeof value) return "$n" + value.toString(10);
   throw Error(
     "Type " +
       typeof value +

compiled/facebook-www/ReactFlightDOMRelayServer-prod.modern.js

@@ -909,13 +909,7 @@ function resolveModelToJSON(request, parent, key, value) {
     element.set(value, key);
     return "$" + key.toString(16);
   }
-  if ("bigint" === typeof value)
-    throw Error(
-      "BigInt (" +
-        value +
-        ") is not yet supported in Client Component props." +
-        describeObjectForErrorMessage(parent, key)
-    );
+  if ("bigint" === typeof value) return "$n" + value.toString(10);
   throw Error(
     "Type " +
       typeof value +