Add a conversion from TransitiveFilter to SliceOptions.

[jreiffers]

Summary

The previous attempt at backwards compatibility was insufficient.

mlir/include/mlir/Analysis/SliceAnalysis.h

struct SliceOptions {
   /// This can be used in particular to limit the propagation to a given Scope
   /// or to avoid passing through certain types of operation in a configurable
   /// manner.
   using TransitiveFilter = std::function<bool(Operation *)>;
   TransitiveFilter filter = nullptr;
 
   /// Include the top level op in the slice.
   bool inclusive = false;
+
+  // TODO: Remove this alias once downstream users are updated.
+  SliceOptions() {}
+  SliceOptions(TransitiveFilter filter) : filter(std::move(filter)) {}
 };
 
 // TODO: Remove this alias once downstream users are updated.
 using TransitiveFilter = SliceOptions::TransitiveFilter;
 
 struct BackwardSliceOptions : public SliceOptions {
   /// When omitBlockArguments is true, the backward slice computation omits
   /// traversing any block arguments. When omitBlockArguments is false, the