bump maximum UnixSocket message size

Summary:
The takeover data for a monorepo that as loaded millions of indoes has exceeded the previous limit of 512 MiB causing takeover to crash on macOS where INodes are not unloaded.

Bump to 1024 MiB to minimize to the chance of crashing under these conditions.

Reviewed By: genevievehelsel

Differential Revision: D63511162

fbshipit-source-id: ad048a07b6ee6b09d0c596ae41f23fb3c810645e

eden/common/utils/UnixSocket.h

@@ -403,10 +403,9 @@ class UnixSocket : public folly::DelayedDestruction,
   uint16_t registeredIOEvents_{0};
   bool closeStarted_{false};
 
-  // The takeover data for a single monorepo can exceed 20 MB.  Allow
   // sufficiently large transfers while limiting the risk of making too large
   // of an allocation given bogus data.
-  uint32_t maxDataLength_ = 512 * 1024 * 1024;
+  uint32_t maxDataLength_ = 1024 * 1024 * 1024;
   uint32_t maxFiles_ = 100000;
   std::chrono::milliseconds sendTimeout_{250};