Debugger: Implement remainder of #12729.

UserInterfaceListener:
- Add request hook for writing a core file. Implement in TeamDebugger.

Jobs/WriteCoreFileJob:
- Add new job to actually dispatch the core file request via the debugger
  interface.

Team{::Listener}
- Add listener event + hook for notifications when a core file gets written.
  Implement in CLI.

CliContext:
- Add event flag for core file changed.

CommandLineUserInterface:
- Add 'write-core' command. This optionally takes a path to write the core to,
  otherwise one is automatically generated by, similarly to debug reports. As
  such, one can now generate cores for things like app_server and registrar
  crashes if desired, in addition to reports.

src/apps/debugger/controllers/TeamDebugger.cpp

@@ -846,6 +846,16 @@ TeamDebugger::MessageReceived(BMessage* message)
 			break;
 		}
 
+		case MSG_WRITE_CORE_FILE:
+		{
+			entry_ref ref;
+			if (message->FindRef("target", &ref) != B_OK)
+				break;
+
+			_HandleWriteCoreFile(ref);
+			break;
+		}
+
 		case MSG_THREAD_STATE_CHANGED:
 		{
 			int32 threadID;
@@ -1304,6 +1314,15 @@ TeamDebugger::DebugReportRequested(entry_ref* targetPath)
 }
 
 
+void
+TeamDebugger::WriteCoreFileRequested(entry_ref* targetPath)
+{
+	BMessage message(MSG_WRITE_CORE_FILE);
+	message.AddRef("target", targetPath);
+	PostMessage(&message);
+}
+
+
 void
 TeamDebugger::TeamRestartRequested()
 {
@@ -2305,6 +2324,19 @@ TeamDebugger::_HandleEvaluateExpression(SourceLanguage* language,
 }
 
 
+void
+TeamDebugger::_HandleWriteCoreFile(const entry_ref& targetPath)
+{
+	status_t result = fWorker->ScheduleJob(
+		new(std::nothrow) WriteCoreFileJob(fTeam, fDebuggerInterface,
+			targetPath));
+	if (result != B_OK) {
+		_NotifyUser("Write Core File", "Failed to write core file: %s",
+			strerror(result));
+	}
+}
+
+
 status_t
 TeamDebugger::_HandleSetArguments(int argc, const char* const* argv)
 {