PR #12171: [XLA: GPU] add more checks for barrierCmd unittest
PR #12171: [XLA: GPU] add more checks for barrierCmd unittest

Imported from GitHub PR https://github.com/openxla/xla/pull/12171


Copybara import of the project:

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30f9abd60c34f01c5fc77f7745275141130afce6 by Shawn Wang <shawnw@nvidia.com>:

add more checks for barrierCmd

Merging this change closes #12171

FUTURE_COPYBARA_INTEGRATE_REVIEW=https://github.com/openxla/xla/pull/12171 from shawnwang18:shawnw/more_barrier_cmd_test 30f9abd60c34f01c5fc77f7745275141130afce6
