[XLA:MHLO->HLO] Allow partially-set parameter tuple sharding to exist by filling in the missing sharding elements with replicated sharding. (This is what is done for the missing shardings in the result tuple.)

[XLA:MHLO->HLO] Allow partially-set parameter tuple sharding to exist by filling in the missing sharding elements with replicated sharding. (This is what is done for the missing shardings in the result tuple.) #48137