This patch adds a `getStaticTripCount` to the LoopLikeOpInterface,
allowing loops to optionally return a static trip count when possible.
This is implemented on SCF ForOp, revamping the implementation of
`constantTripCount`, removing redundant duplicate implementations from
SCF.cpp.

See https://github.com/llvm/llvm-project/pull/147168 for more info.

The greedy rewriter is used in many different flows and it has a lot of
convenience (work list management, debugging actions, tracing, etc). But
it combines two kinds of greedy behavior 1) how ops are matched, 2)
folding wherever it can.

These are independent forms of greedy and leads to inefficiency. E.g.,
cases where one need to create different phases in lowering and is
required to applying patterns in specific order split across different
passes. Using the driver one ends up needlessly retrying folding/having
multiple rounds of folding attempts, where one final run would have
sufficed.

Of course folks can locally avoid this behavior by just building their
own, but this is also a common requested feature that folks keep on
working around locally in suboptimal ways.

For downstream users, there should be no behavioral change. Updating
from the deprecated should just be a find and replace (e.g., `find ./
-type f -exec sed -i
's|applyPatternsAndFoldGreedily|applyPatternsGreedily|g' {} \;` variety)
as the API arguments hasn't changed between the two.

fixed https://github.com/llvm/llvm-project/issues/119378

Allow speculative execution and predicate results per stage.

The pattern rewriter documentation states that "*all* IR mutations [...]
are required to be performed via the `PatternRewriter`." This commit
adds two functions that were missing from the rewriter API:
`moveOpBefore` and `moveOpAfter`.

After an operation was moved, the `notifyOperationInserted` callback is
triggered. This allows listeners such as the greedy pattern rewrite
driver to react to IR changes.

This commit narrows the discrepancy between the kind of IR modification
that can be performed and the kind of IR modifications that can be
listened to.

Support loops without static boundaries. Since the number of iteration
is not known we need to predicate prologue and epilogue in case the
number of iterations is smaller than the number of stages.

This patch includes work from @chengjunlu

Add a new interface method that returns the yielded values.
    
Also add a verifier that checks the number of inits/iter_args/yielded
values. Most of the checked invariants (but not all of them) are already
covered by the `RegionBranchOpInterface`, but the `LoopLikeOpInterface`
now provides (additional) error messages that are easier to read.

`affine::replaceForOpWithNewYields` and `replaceLoopWithNewYields` (for
"scf.for") are now interface methods and additional loop-carried
variables can now be added to "scf.for"/"affine.for" uniformly. (No more
`TypeSwitch` needed.)

Note: `scf.while` and other loops with loop-carried variables can
implement `replaceWithAdditionalYields`, but to keep this commit small,
that is not done in this commit.