Fix TPR to explicitly prevent usage on big-endian architectures

Summary:
Fix TPR to explicitly prevent usage on big-endian architectures where byte-order issues would cause routing errors.

https://fb.workplace.com/groups/592309277200280/permalink/659068030524404/

Detailed document explaining the issue:
https://docs.google.com/document/d/1kOW2XtuWPV3hkfS7dCGZyIJoMNUmzwSQg53L6cxpr84/edit?usp=sharing

Reviewed By: avasylev

Differential Revision: D84927432

fbshipit-source-id: 4c510aac61b083ebf9ef2d19a575ebe0aa874b7f

Author: tagrawal03

katran/tpr/TcpPktRouter.cpp

@@ -31,6 +31,14 @@ TcpPktRouter::~TcpPktRouter() {
 folly::Expected<folly::Unit, std::system_error> TcpPktRouter::init(
     bool pollStats) {
   CHECK(!isInitialized_);
+
+#if defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+  static_assert(
+      false,
+      "TPR cannot run on big-endian architecture due to server_id byte-order "
+      "requirements");
+#endif
+
   auto res = BpfUtil::init();
   if (res.hasError()) {
     return makeError(res.error(), __func__);