[lldb] Make use of Scripted{Python,}Interface for ScriptedThreadPlan (#70392)

This patch makes ScriptedThreadPlan conforming to the ScriptedInterface
& ScriptedPythonInterface facilities by introducing 2
ScriptedThreadPlanInterface & ScriptedThreadPlanPythonInterface classes.

This allows us to get rid of every ScriptedThreadPlan-specific SWIG
method and re-use the same affordances as other scripting offordances,
like Scripted{Process,Thread,Platform} & OperatingSystem.

To do so, this adds new transformer methods for `ThreadPlan`, `Stream` &
`Event`, to allow the bijection between C++ objects and their python
counterparts.

Signed-off-by: Med Ismail Bennani <ismail@bennani.ma>

lldb/source/Plugins/ScriptInterpreter/Python/Interfaces/ScriptedPythonInterface.cpp

@@ -26,6 +26,15 @@ ScriptedPythonInterface::ScriptedPythonInterface(
     ScriptInterpreterPythonImpl &interpreter)
     : ScriptedInterface(), m_interpreter(interpreter) {}
 
+template <>
+void ScriptedPythonInterface::ReverseTransform(
+    lldb_private::Stream *&original_arg, python::PythonObject transformed_arg,
+    Status &error) {
+  Stream *s = ExtractValueFromPythonObject<Stream *>(transformed_arg, error);
+  *original_arg = *s;
+  original_arg->PutCString(static_cast<StreamString *>(s)->GetData());
+}
+
 template <>
 StructuredData::ArraySP
 ScriptedPythonInterface::ExtractValueFromPythonObject<StructuredData::ArraySP>(
@@ -48,12 +57,33 @@ Status ScriptedPythonInterface::ExtractValueFromPythonObject<Status>(
   if (lldb::SBError *sb_error = reinterpret_cast<lldb::SBError *>(
           python::LLDBSWIGPython_CastPyObjectToSBError(p.get())))
     return m_interpreter.GetStatusFromSBError(*sb_error);
-  else
-    error.SetErrorString("Couldn't cast lldb::SBError to lldb::Status.");
+  error.SetErrorString("Couldn't cast lldb::SBError to lldb::Status.");
 
   return {};
 }
 
+template <>
+Event *ScriptedPythonInterface::ExtractValueFromPythonObject<Event *>(
+    python::PythonObject &p, Status &error) {
+  if (lldb::SBEvent *sb_event = reinterpret_cast<lldb::SBEvent *>(
+          python::LLDBSWIGPython_CastPyObjectToSBEvent(p.get())))
+    return m_interpreter.GetOpaqueTypeFromSBEvent(*sb_event);
+  error.SetErrorString("Couldn't cast lldb::SBEvent to lldb_private::Event.");
+
+  return nullptr;
+}
+
+template <>
+Stream *ScriptedPythonInterface::ExtractValueFromPythonObject<Stream *>(
+    python::PythonObject &p, Status &error) {
+  if (lldb::SBStream *sb_stream = reinterpret_cast<lldb::SBStream *>(
+          python::LLDBSWIGPython_CastPyObjectToSBStream(p.get())))
+    return m_interpreter.GetOpaqueTypeFromSBStream(*sb_stream);
+  error.SetErrorString("Couldn't cast lldb::SBStream to lldb_private::Stream.");
+
+  return nullptr;
+}
+
 template <>
 lldb::DataExtractorSP
 ScriptedPythonInterface::ExtractValueFromPythonObject<lldb::DataExtractorSP>(