Remove remaining reference to torchgen.gen_executorch

Summary:
Fixes #11232
This is part of an effort to remove ExecuTorch related codegen code in pytorch/pytorch's torchgen module. We need to remove `torchgen.gen_executorch` in ExecuTorch and use `executorch.codegen.gen` instead.

Differential Revision: D75800153

Author: larryliu0820

codegen/test/test_executorch_custom_ops.py

@@ -16,7 +16,7 @@
 import torchgen
 from executorch.codegen.api.custom_ops import ComputeNativeFunctionStub
 from executorch.codegen.model import ETKernelIndex
-from torchgen.gen_executorch import gen_headers
+from executorch.codegen.gen import gen_headers
 from torchgen.model import Location, NativeFunction
 from torchgen.selective_build.selector import SelectiveBuilder
 from torchgen.utils import FileManager

codegen/test/test_executorch_gen.py

@@ -14,7 +14,7 @@
 
 from executorch.codegen.model import ETKernelIndex, ETKernelKey
 from torchgen.gen import LineLoader
-from torchgen.gen_executorch import (
+from executorch.codegen.gen import (
     ComputeCodegenUnboxedKernels,
     gen_functions_declarations,
     parse_yaml_files,

third-party/TARGETS

@@ -81,18 +81,6 @@ runtime.python_binary(
     _is_external_target = True,
 )
 
-runtime.python_binary(
-    name = "gen_executorch",
-    main_module = "torchgen.gen_executorch",
-    visibility = [
-        "PUBLIC",
-    ],
-    deps = [
-        ":torchgen",
-    ],
-    _is_external_target = True,
-)
-
 runtime.filegroup(
     name = "aten_src_path",
     srcs = [

tools/cmake/Codegen.cmake

@@ -91,8 +91,9 @@ function(generate_bindings_for_kernels)
     OUTPUT_STRIP_TRAILING_WHITESPACE
   )
   file(GLOB_RECURSE _torchgen_srcs "${torchgen-out}/*.py")
+  # Not using module executorch.codegen.gen because it's not installed yet.
   set(_gen_command
-      "${PYTHON_EXECUTABLE}" -m torchgen.gen_executorch
+      "${PYTHON_EXECUTABLE}" ${EXECUTORCH_ROOT}/codegen/gen.py
       --source-path=${EXECUTORCH_ROOT}/codegen --install-dir=${_out_dir}
       --tags-path=${torchgen-out}/packaged/ATen/native/tags.yaml
       --aten-yaml-path=${torchgen-out}/packaged/ATen/native/native_functions.yaml