Add get parent to filesystem

LiteRT-PiperOrigin-RevId: 820520339

Author: LukeBoyer

litert/core/filesystem.cc

@@ -149,4 +149,9 @@ Expected<void> MkDir(absl::string_view path) {
   return {};
 }
 
+Expected<std::string> Parent(absl::string_view path) {
+  auto std_path = MakeStdPath(path);
+  return std_path.parent_path().generic_string();
+}
+
 }  // namespace litert::internal

litert/core/filesystem.h

@@ -56,6 +56,9 @@ Expected<std::string> Filename(absl::string_view path);
 // Make a new directory at the given path.
 Expected<void> MkDir(absl::string_view path);
 
+// Get the parent directory of the given path.
+Expected<std::string> Parent(absl::string_view path);
+
 }  // namespace litert::internal
 
 #endif  // ODML_LITERT_LITERT_CORE_FILESYSTEM_H_