xla

Add an option to accept a callback in the remat pass to allow additional operations on the rematerialized instructions.

[xla:cpu:xnn] Delete unused workspace

Integrate LLVM at llvm/llvm-project@e68a20e0b762

Add option to enable coordination service client to recover.

[xla:cpu] Add Thunk::ExecuteMayBlock() flag and a ThunkExecutor optimization to parallelize processing thunks that might block execution thread