[mlir][Interfaces] Add `promoteIfSingleIteration` to `LoopLikeOpInterface`

[mlir][Interfaces] Add `promoteIfSingleIteration` to `LoopLikeOpInterface`

There are existing implementations for `scf.for`, `scf.forall` and `affine.for`. This revision adds an interface method to the `LoopLikeOpInterface`.

* `scf.forall` now implements the `LoopLikeOpInterface`.
* The implementations of `scf.for` and `scf.forall` become interface method implementations. `affine.for` remains as is for the moment. (The implementation of `promoteIfSingleIteration` depepends on helper functions from `MLIRAffineAnalysis`, which cannot be used from `MLIRAffineDialect`, where the interface is currently implemented.)
* More efficient implementations of `promoteIfSingleIteration`. In particular, the `scf.forall` operation now inlines operations instead of cloning them. This also preserves handles when used from the transform dialect.

Differential Revision: https://reviews.llvm.org/D154343