chore: import upstream snapshot with attribution

tensorflow/compiler/mlir/tfrt/backend_compiler.h

@@ -0,0 +1,41 @@
+/* Copyright 2023 The TensorFlow Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+==============================================================================*/
+
+#ifndef TENSORFLOW_COMPILER_MLIR_TFRT_BACKEND_COMPILER_H_
+#define TENSORFLOW_COMPILER_MLIR_TFRT_BACKEND_COMPILER_H_
+
+#include "absl/status/status.h"
+#include "mlir/IR/BuiltinOps.h"  // from @llvm-project
+#include "mlir/IR/DialectRegistry.h"  // from @llvm-project
+#include "tensorflow/core/tfrt/runtime/runtime.h"
+
+namespace tensorflow {
+
+class BackendCompiler {
+ public:
+  virtual ~BackendCompiler();
+
+  virtual void GetDependentDialects(mlir::DialectRegistry& registry) const {}
+
+  // Compile the `module` in TF dialect. The result module should be also in TF
+  // dialect.
+  virtual absl::Status CompileTensorflow(
+      tfrt_stub::ModelRuntimeContext& model_context,
+      mlir::ModuleOp module) const = 0;
+};
+
+}  // namespace tensorflow
+
+#endif  // TENSORFLOW_COMPILER_MLIR_TFRT_BACKEND_COMPILER_H_