libtensorflow may be redundant

I tested out dlopen and dlsym on libx10 using Swift REPL, and I could load the symbol TF_Version just like with libtensorflow. I also succeeded in compiling philipturner/swift-for-tensorflow (with the files crashing AutoDiff removed), even after the libtensorflow binary was removed. Check and run the Swift tests yourself, though.

If this is indeed the case, then we can halve the storage space of TensorFlow binaries cached on the internet, and halve download time. The existing binaries are 400 MB each. For reference, that's the size of a Swift toolchain, which takes 30 seconds to download on Google Colab. If we didn't remove libtensorflow from the build process, the total download time for S4TF would become 1 min 30 seconds.

Also, this would explain why I only see "x10" referenced as a linked library in C modulemaps. "tensorflow" is mentioned nowhere. Also, the x10 binary is slightly larger than tensorflow (+30 MB on arm64 macOS). It would make sense if x10 was tensorflow with a few C++ files from s4tf appended into it.