Re-land: Optimize dot(DynamicSlice(ConstA), ConstantB) by memoizing dot(ConstA, ConstB)

Re-land: Optimize dot(DynamicSlice(ConstA), ConstantB) by memoizing dot(ConstA, ConstB)

Make transformation when ConstA and ConstB are 2D, and DynamicSlice is slicing a full row, column respectively.
Handle:
dot(DynamicSlice(Index, ConstA), ConstB) => DynamicSlice(Index, dot*(ConstA, ConstB));
and
dot(ConstA, DynamicSlice(Index, ConstB)) => DynamicSlice(Index, dot*(ConstA, ConstB));

Reason to roll forward: Previous issue of getting out of memory errors when generating LLVM constants was resolved by CSE-ing constants before allocation.

PiperOrigin-RevId: 195853680