debug(traceback): 输出 InstallSymbol 赋值日志

每个文件打印 TracebackInstallSymbol，确认 main 模块是否拿到 3fe9e5dc351f3d26.Install。

lib/Projectrans/Phase2Translator.py

@@ -2375,6 +2375,9 @@ class Phase2Translator:
                         break
             if _tb_sha1 is not None:
                 trans.translator.TracebackInstallSymbol = f'{_tb_sha1}.Install'
+            _vlog().info(
+                f"[traceback] InstallSymbol={getattr(trans.translator, 'TracebackInstallSymbol', None)}"
+                f"  file={os.path.basename(src_path)}")
         trans.SliceLevel = self.slice_level
         trans.translator.SliceLevel = self.slice_level
         trans.translator.SliceCount = 0