[lldb] Only send "posix" error codes through the gdb-remote protocol

The other side has no way of telling which namespace do these codes
belong to, so mashing them all together is not very helpful.

I'm mainly doing this to simplify some code in a pending patch
<https://github.com/llvm/llvm-project/pull/106774/files#r1752628604>,
and I've picked the posix error category semi-randomly. If we wanted to
be serious about assigning meaning to these error codes, we should
create a special error category for "gdb errors".

Author: labath

lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.cpp

@@ -103,13 +103,14 @@ GDBRemoteCommunicationServer::SendErrorResponse(uint8_t err) {
 
 GDBRemoteCommunication::PacketResult
 GDBRemoteCommunicationServer::SendErrorResponse(const Status &error) {
+  uint8_t code = error.GetType() == eErrorTypePOSIX ? error.GetError() : 0xff;
   if (m_send_error_strings) {
     lldb_private::StreamString packet;
-    packet.Printf("E%2.2x;", static_cast<uint8_t>(error.GetError()));
+    packet.Printf("E%2.2x;", code);
     packet.PutStringAsRawHex8(error.AsCString());
     return SendPacketNoLock(packet.GetString());
-  } else
-    return SendErrorResponse(error.GetError());
+  }
+  return SendErrorResponse(code);
 }
 
 GDBRemoteCommunication::PacketResult

lldb/unittests/Process/gdb-remote/GDBRemoteCommunicationServerTest.cpp

@@ -12,6 +12,7 @@
 #include "Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.h"
 #include "lldb/Utility/Connection.h"
 #include "lldb/Utility/UnimplementedError.h"
+#include "lldb/lldb-enumerations.h"
 
 namespace lldb_private {
 namespace process_gdb_remote {
@@ -25,7 +26,7 @@ TEST(GDBRemoteCommunicationServerTest, SendErrorResponse_ErrorNumber) {
 
 TEST(GDBRemoteCommunicationServerTest, SendErrorResponse_Status) {
   MockServerWithMockConnection server;
-  Status status(0x42, lldb::eErrorTypeGeneric, "Test error message");
+  Status status(0x42, lldb::eErrorTypePOSIX, "Test error message");
   server.SendErrorResponse(status);
 
   EXPECT_THAT(