Add a temporary alias for TransitiveFilter.

[jreiffers]

Summary

This type was removed in D151520, but downstream dependencies use it. By
introducing a temporary allias, we can give these dependencies a chance to
update their uses of the type and give them a chance to migrate without
breakages.

mlir/include/mlir/Analysis/SliceAnalysis.h

struct SliceOptions {
   /// 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.
+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
   /// backward slice computation traverses block arguments and asserts that the
   /// parent op has a single region with a single block.
   bool omitBlockArguments = false;
 };