Add lowerings for vector transfers.
Add lowerings for vector transfers.

Only in-bounds, maskless, 1d transfers are supported. We'll
probably need masks eventually, but not yet.

FUTURE_COPYBARA_INTEGRATE_REVIEW=https://github.com/openxla/xla/pull/13265 from openxla:refactor_runner 04cb8447c90d46f171e5a0f0261e81f8690d1ab4
