PR #11514: Move cublasLT workspace allocation to buffer assignment
PR #11514: Move cublasLT workspace allocation to buffer assignment

Imported from GitHub PR https://github.com/openxla/xla/pull/11514

Move cublasLT workspace allocation to buffer assignment to support command buffer lowering
Copybara import of the project:

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7a448b05a54345c0cb15a47c9dc45558255c9656 by Shawn Wang <shawnw@nvidia.com>:

Move cublasLT workspace allocation to buffer assignment to support command buffer lowering

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16e6efe960d92825bed0a0237a374f7980baf5d2 by Shawn Wang <shawnw@nvidia.com>:

set workspace size

Merging this change closes #11514

FUTURE_COPYBARA_INTEGRATE_REVIEW=https://github.com/openxla/xla/pull/11514 from shawnwang18:shawnw/cublaslt_command_buffer 16e6efe960d92825bed0a0237a374f7980baf5d2
