*   xla.experimental.compile is deprecated, use
    `tf.function(experimental_compile=True)` instead.
*   Adds `tf.function.experimental_get_compiler_ir` which returns compiler IR
    (currently 'hlo' and 'optimized_hlo') for given input for given function.

### Security:

*   Fixes an undefined behavior causing a segfault in `tf.raw_ops.Switch`,