swift

3c2d5d1d - Reduce toolchain size by preserving TensorFlow library symlinks. (#27233)

Reduce toolchain size by preserving TensorFlow library symlinks. (#27233) Bazel produces multiple TensorFlow library artifacts: ``` $ ls -alh tensorflow/bazel-bin/tensorflow 18B libtensorflow.so -> libtensorflow.so.1 23B libtensorflow.so.1 -> libtensorflow.so.1.14.0 277M libtensorflow.so.1.14.0 ``` Previously, TensorFlow libraries were copied via `cp -p`. This did not preserve symlinks, leading to library duplication: ``` $ ls -alh <TOOLCHAIN_BEFORE>.xctoolchain/usr/lib/swift/macosx 18B libtensorflow.so -> libtensorflow.so.1 277M libtensorflow.so.1 277M libtensorflow.so.1.14.0 # duplicate library ``` Now, `cp -a` is used, which preserves symlinks: ``` $ ls -alh <TOOLCHAIN_AFTER>.xctoolchain/usr/lib/swift/macosx 18B libtensorflow.so -> libtensorflow.so.1 277M libtensorflow.so.1 ``` This combined with removing libtensorflow_framework.so dependency (https://github.com/apple/swift/pull/27029) led to a macOS toolchain size reduction from 3.99 GB to 3.62 GB on the tensorflow-0.5 branch.