[nnc] Started codegenning some external calls (#58118)

Summary:
Currently only supports native ops that have all tensor arguments, an out variant, and no kwargs.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/58118

Reviewed By: ejguan

Differential Revision: D28421323

Pulled By: Chillee

fbshipit-source-id: 1c75c900415deca63fcc0e496e3bac126f21bf49
diff --git a/tools/build_variables.bzl b/tools/build_variables.bzl
index 8638aaa..2d75671 100644
--- a/tools/build_variables.bzl
+++ b/tools/build_variables.bzl
@@ -296,6 +296,7 @@
     "torch/csrc/jit/runtime/static/ops.cpp",
     "torch/csrc/jit/runtime/static/passes.cpp",
     "torch/csrc/jit/tensorexpr/external_functions.cpp",
+    "torch/csrc/jit/tensorexpr/external_functions_codegen.cpp",
 ]
 
 libtorch_core_sources = sorted(core_sources_common + core_sources_full + core_trainer_sources)