Fix eigh JVP to ensure that both the primal and tangents of the eigen… (#3550)
* Fix eigh JVP to ensure that both the primal and tangents of the eigenvalues are real.
Add test to jax.test_util.check_jvp that ensure the primals and both the primals and tangents produced by a JVP rule have identical types.
* Cast input to static indexing grad tests to a JAX array so new type check passes.