[CommandInterpreter] Remove scripting language argument. (NFC)

The script language argument was passed from the debugger to the command
interpreter, only to call SetScriptLanguage on the debugger again. It
wasn't even used to initialize the script interpreter, because that
would query the debugger again. This patch removes the needless back and
forth.

llvm-svn: 359346
diff --git a/lldb/source/Core/Debugger.cpp b/lldb/source/Core/Debugger.cpp
index 3ff9232..9c56905 100644
--- a/lldb/source/Core/Debugger.cpp
+++ b/lldb/source/Core/Debugger.cpp
@@ -765,8 +765,8 @@
       m_terminal_state(), m_target_list(*this), m_platform_list(),
       m_listener_sp(Listener::MakeListener("lldb.Debugger")),
       m_source_manager_up(), m_source_file_cache(),
-      m_command_interpreter_up(llvm::make_unique<CommandInterpreter>(
-          *this, eScriptLanguageDefault, false)),
+      m_command_interpreter_up(
+          llvm::make_unique<CommandInterpreter>(*this, false)),
       m_input_reader_stack(), m_instance_name(), m_loaded_plugins(),
       m_event_handler_thread(), m_io_handler_thread(),
       m_sync_broadcaster(nullptr, "lldb.debugger.sync"),