[Mlir-commits] [mlir] [MLIR][SCF] fix scf.index_switch fold convergence (#98535) (PR #98680)

[Keyi Zhang]

Kuree wrote:

@joker-eph This is mentioned in the [MLIR doc](https://mlir.llvm.org/docs/Canonicalization/#canonicalizing-with-the-fold-method).

> ```
> /// Note that this mechanism cannot be used to remove 0-result operations.
> LogicalResult MyOp::fold(FoldAdaptor adaptor,
>                         SmallVectorImpl<OpFoldResult> &results) {
>   ...
> }
> ```

https://github.com/llvm/llvm-project/pull/98680