[lldb][NFCI] Change type of SBDebugger::m_instance_name

This doesn't need to be in the ConstString StringPool. There's little
benefit to having these be unique, and we don't need fast comparisons on
them.

Differential Revision: https://reviews.llvm.org/D151524

lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp

@@ -408,7 +408,7 @@ ScriptInterpreterPythonImpl::ScriptInterpreterPythonImpl(Debugger &debugger)
       m_session_dict(PyInitialValue::Invalid),
       m_sys_module_dict(PyInitialValue::Invalid), m_run_one_line_function(),
       m_run_one_line_str_global(),
-      m_dictionary_name(m_debugger.GetInstanceName().AsCString()),
+      m_dictionary_name(m_debugger.GetInstanceName()),
       m_active_io_handler(eIOHandlerNone), m_session_is_active(false),
       m_pty_secondary_is_open(false), m_valid_session(true), m_lock_count(0),
       m_command_thread_state(nullptr) {