Add pattern that converts a `tensor.expand_shape` op to a more static
form.
This matches the pattern: `tensor.cast` -> `tensor.expand_shape` if it
has a foldable `tensor.cast` and some constant foldable `output_shape`
operands for the `tensor.expand_shape`. This makes the
`tensor.expand_shape` more static, as well as allowing the static
information to be propagated further down in the program.
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