Merged commit includes the following changes:

163914294  by annarev:

    Refactors build target for gradients_impl to allow code to depend on the gradient generation but not the gradients themselves.

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163913011  by A. Unique TensorFlower:

    Use an LLVM-IR version of vector hyperbolic tangent.

    This lets us:

     - Inline routine where it is called, eliminated call overhead.
     - Use AVX instructions in JITed code even if Tensorflow was not built with -mavx.

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163909534  by A. Unique TensorFlower:

    Add tensorflow-android to standard TF maven artifacts.

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163908704  by A. Unique TensorFlower:

    Go: Update generated wrapper functions for TensorFlow ops.

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163907709  by A. Unique TensorFlower:

    Update ops-related pbtxt files.

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163907497  by A. Unique TensorFlower:

    Remove old TensorFlow Serving landing page in prepartion for new TF
    Serving landing page.  Fix bad leftnav.

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163906225  by alive:

    Refactors build target for gradients_impl to allow code to depend on the gradient generation but not the gradients themselves.

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PiperOrigin-RevId: 163914294