Fix TestImport for Windows by ensuring backslashes in the directory paths are properly escaped in Python.

[amccarth]

Summary

The Python import works by ensuring the directory of the module or package is in sys.path, and then it does a Python import foo. The original code was not escaping the backslashes in the directory path, so this wasn't working.

(Discovered after chasing alternative ways of importing a module from a path.)

[zturner]

Just occurred to me that it would be nice if PythonDataObjects exposed a way to get the underlying PythonObject of various common globals like sys.path etc. Then we could just do something like

PythonDataObjects::QuickVars::SysPath.Insert(0, Escape(directory));

But, that's outside the scope of this patch, so lgtm.

source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp

ScriptInterpreterPython::LoadScriptingModule(const char *pathname, bool can_reload, bool init_session, lldb_private::Error &error,
     lldb::DebuggerSP debugger_sp = m_interpreter.GetDebugger().shared_from_this();
 
     {
         FileSpec target_file(pathname, true);
         std::string basename(target_file.GetFilename().GetCString());
         
         StreamString command_stream;
 
-        // Before executing Pyton code, lock the GIL.
+        // Before executing Python code, lock the GIL.
         Locker py_lock (this,
                         Locker::AcquireLock      | (init_session ? Locker::InitSession     : 0) | Locker::NoSTDIN,
                         Locker::FreeAcquiredLock | (init_session ? Locker::TearDownSession : 0));
         
         if (target_file.GetFileType() == FileSpec::eFileTypeInvalid ||
             target_file.GetFileType() == FileSpec::eFileTypeUnknown)
         {
             // if not a valid file of any sort, check if it might be a filename still
             // dot can't be used but / and \ can, and if either is found, reject
             if (strchr(pathname,'\\') || strchr(pathname,'/'))
             {
                 error.SetErrorString("invalid pathname");
                 return false;
             }
             basename = pathname; // not a filename, probably a package of some sort, let it go through
         }
         else if (target_file.GetFileType() == FileSpec::eFileTypeDirectory ||
                  target_file.GetFileType() == FileSpec::eFileTypeRegular ||
                  target_file.GetFileType() == FileSpec::eFileTypeSymbolicLink)
         {
-            std::string directory(target_file.GetDirectory().GetCString());
-            replace_all(directory,"'","\\'");
-            
+            std::string directory = target_file.GetDirectory().GetCString();
+            replace_all(directory, "\\", "\\\\");
+            replace_all(directory, "'", "\\'");
             // now make sure that Python has "directory" in the search path
             StreamString command_stream;
             command_stream.Printf("if not (sys.path.__contains__('%s')):\n    sys.path.insert(1,'%s');\n\n",
                                   directory.c_str(),
                                   directory.c_str());
             bool syspath_retval = ExecuteMultipleLines(command_stream.GetData(), ScriptInterpreter::ExecuteScriptOptions().SetEnableIO(false).SetSetLLDBGlobals(false)).Success();
             if (!syspath_retval)
             {
                 error.SetErrorString("Python sys.path handling failed");
                 return false;
             }
-            
             // strip .py or .pyc extension
             ConstString extension = target_file.GetFileNameExtension();
             if (extension)
             {
                 if (::strcmp(extension.GetCString(), "py") == 0)
                     basename.resize(basename.length()-3);
                 else if(::strcmp(extension.GetCString(), "pyc") == 0)
                     basename.resize(basename.length()-4);
lldb::DebuggerSP debugger_sp = m_interpreter.GetDebugger().shared_from_this();
         if (was_imported)
         {
             if (!was_imported_locally)
                 command_stream.Printf("import %s ; reload_module(%s)",basename.c_str(),basename.c_str());
             else
                 command_stream.Printf("reload_module(%s)",basename.c_str());
         }
         else
-            command_stream.Printf("import %s",basename.c_str());
-        
+            command_stream.Printf("import %s", basename.c_str());
         error = ExecuteMultipleLines(command_stream.GetData(), ScriptInterpreter::ExecuteScriptOptions().SetEnableIO(false).SetSetLLDBGlobals(false));
         if (error.Fail())
             return false;
         
         // if we are here, everything worked
         // call __lldb_init_module(debugger,dict)
         if (!g_swig_call_module_init (basename.c_str(),
                                       m_dictionary_name.c_str(),