[lldb] Use Py_InitializeFromConfig with Python >= 3.8 (NFC) (llvm#114112)

This fixes the deprecation warning for Py_SetPythonHome, which was
deprecated in Python 3.11. With this patch, when building against Python
3.8 or later, we now use Py_InitializeFromConfig instead.

Fixes llvm#113475

Author: JDevlieghere

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

@@ -92,7 +92,33 @@ namespace {
 struct InitializePythonRAII {
 public:
   InitializePythonRAII() {
-    InitializePythonHome();
+#if (PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 8) || (PY_MAJOR_VERSION > 3)
+    PyConfig config;
+    PyConfig_InitPythonConfig(&config);
+#endif
+
+#if LLDB_EMBED_PYTHON_HOME
+    static std::string g_python_home = []() -> std::string {
+      if (llvm::sys::path::is_absolute(LLDB_PYTHON_HOME))
+        return LLDB_PYTHON_HOME;
+
+      FileSpec spec = HostInfo::GetShlibDir();
+      if (!spec)
+        return {};
+      spec.AppendPathComponent(LLDB_PYTHON_HOME);
+      return spec.GetPath();
+    }();
+    if (!g_python_home.empty()) {
+#if (PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 8) || (PY_MAJOR_VERSION > 3)
+      PyConfig_SetBytesString(&config, &config.home, g_python_home.c_str());
+#else
+      size_t size = 0;
+      wchar_t *python_home_w = Py_DecodeLocale(g_python_home.c_str(), &size);
+      Py_SetPythonHome(python_home_w);
+      PyMem_RawFree(python_home_w);
+#endif
+    }
+#endif
 
     // The table of built-in modules can only be extended before Python is
     // initialized.
@@ -117,15 +143,22 @@ struct InitializePythonRAII {
       PyImport_AppendInittab("_lldb", LLDBSwigPyInit);
     }
 
+#if (PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 8) || (PY_MAJOR_VERSION > 3)
+    config.install_signal_handlers = 0;
+    Py_InitializeFromConfig(&config);
+    PyConfig_Clear(&config);
+    InitializeThreadsPrivate();
+#else
 // Python < 3.2 and Python >= 3.2 reversed the ordering requirements for
 // calling `Py_Initialize` and `PyEval_InitThreads`.  < 3.2 requires that you
 // call `PyEval_InitThreads` first, and >= 3.2 requires that you call it last.
-#if (PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 2) || (PY_MAJOR_VERSION > 3)
+#if (PY_MAJOR_VERSION == 3 && PY_MINOR_VERSION >= 2)
     Py_InitializeEx(0);
     InitializeThreadsPrivate();
 #else
     InitializeThreadsPrivate();
     Py_InitializeEx(0);
+#endif
 #endif
   }
 
@@ -142,32 +175,6 @@ struct InitializePythonRAII {
   }
 
 private:
-  void InitializePythonHome() {
-#if LLDB_EMBED_PYTHON_HOME
-    typedef wchar_t *str_type;
-    static str_type g_python_home = []() -> str_type {
-      const char *lldb_python_home = LLDB_PYTHON_HOME;
-      const char *absolute_python_home = nullptr;
-      llvm::SmallString<64> path;
-      if (llvm::sys::path::is_absolute(lldb_python_home)) {
-        absolute_python_home = lldb_python_home;
-      } else {
-        FileSpec spec = HostInfo::GetShlibDir();
-        if (!spec)
-          return nullptr;
-        spec.GetPath(path);
-        llvm::sys::path::append(path, lldb_python_home);
-        absolute_python_home = path.c_str();
-      }
-      size_t size = 0;
-      return Py_DecodeLocale(absolute_python_home, &size);
-    }();
-    if (g_python_home != nullptr) {
-      Py_SetPythonHome(g_python_home);
-    }
-#endif
-  }
-
   void InitializeThreadsPrivate() {
 // Since Python 3.7 `Py_Initialize` calls `PyEval_InitThreads` inside itself,
 // so there is no way to determine whether the embedded interpreter