PR #12912: Overload operator<< for XLA_FFI_DataType
PR #12912: Overload operator<< for XLA_FFI_DataType

Imported from GitHub PR https://github.com/openxla/xla/pull/12912


Copybara import of the project:

--
32908d2d90a89269c655dff6d999bfc974f405a9 by Andrey Portnoy <aportnoy@nvidia.com>:

Overload operator<< for XLA_FFI_DataType

Merging this change closes #12912

FUTURE_COPYBARA_INTEGRATE_REVIEW=https://github.com/openxla/xla/pull/12912 from openxla:aportnoy/improve-ffi-c-api-datatype-error-message 32908d2d90a89269c655dff6d999bfc974f405a9
