Investigate uses of Greedy Pattern Rewrite Driver

There have been two (somewhat) recent changes in the upstream rewrite drivers:

1. The simpler [Walk Pattern Rewrite Driver](https://mlir.llvm.org/docs/PatternRewriter/#walk-pattern-rewrite-driver) has been added for situations where the fixed point iteration of the greedy rewriter is not necessary
2. The usual way to use the Greed Rewriter, `applyPatternsAndFoldGreedily` has been changed to `applyPatternsGreedily` with the decision on whether or not to also fold now configurable via the `GreedyRewriteConfig` parameter. Currently this defaults to still folding.

The TODO here is to investigate which of our passes that use the greedy rewrite driver can be dropped to a simple walk, and which applications of the greedy rewriter can have the folding dropped (and, e.g., moved to a later step in a pipeline).