Synchronize submodules with LLVM at llvm/llvm-project@2016f2c8a76d
Synchronize submodules with LLVM at llvm/llvm-project@2016f2c8a76d

Updates LLVM dependencies to match
[2016f2c8a76d](https://github.com/llvm/llvm-project/commit/2016f2c8a76d).
- llvm-bazel to
  [4c8b546e53ee](https://github.com/google/llvm-bazel/commit/4c8b546e53ee)
- TensorFlow to
[c66a221d8b49](https://github.com/tensorflow/tensorflow/commit/c66a221d8b49)

`./scripts/git/update_to_llvm_syncpoint.py`

Automated submodule bump from .github/workflows/update_llvm_dependent_submodules.yml

COPYBARA_INTEGRATE_REVIEW=https://github.com/google/iree/pull/4344 from google:auto_submodule_update 86e45c5e1b0fab130b82730356632a7365ce1b91
PiperOrigin-RevId: 349589784

iree-org/iree,google/iree,google/iree,google/iree,google/iree,iree-org/iree,iree-org/iree,google/iree,iree-org/iree,google/iree,iree-org/iree,iree-org/iree,iree-org/iree,google/iree