[llvm] [AArch64] Avoid creating a new generic constant in SelectSMETileSlice (PR #203344)

[Gaëtan Bossu via llvm-commits]

https://github.com/gbossu commented:

The fix does make sense after reading the description, but I'm also not sure why this seems to be only a problem here.

> The issue with this is the new constant may not end up in the instruction selection worklist, as this happens after it has been sorted and started processing nodes.

Do you know why this isn't a problem for other DAG combiners? Was it the only one creating a ISD::CONSTANT directly?

https://github.com/llvm/llvm-project/pull/203344