[XLA] Add a utility function to hoist entry program parameters.
[XLA] Add a utility function to hoist entry program parameters.

Hoisting these to the beginning of the computation increase opportunities to
prefetch them. This does not increase the amount of memory needed since these
buffers are live throughout the program.

PiperOrigin-RevId: 432484598

google/jax,google/jax,google/jax,google/jax