launcher: option to close the terminal after a clean exit (#1869)

launcher: close the terminal after a clean exit and run several games at once

Co-authored-by: nmzik <Nmzik@mail.ru>

src/loader/loadExec.cpp

@@ -149,7 +149,8 @@ int LoadExec(const char* path, const char* const argv[]) {
 	}
 	CloseHandle(process.hThread);
 	CloseHandle(process.hProcess);
-	std::quick_exit(0);
+	// Nonzero, or the launcher's "cmd /K ... && exit" closes the console the new process shares.
+	std::quick_exit(1);
 #else
 	std::ifstream            command("/proc/self/cmdline", std::ios::binary);
 	std::vector<std::string> host_arguments;