This PR fixes a bug where LICM incorrectly allowed buffer semantics,
which could lead to a crash. Fixes #129416.

Reverts llvm/llvm-project#120302

Enable ops with only read side effects in scf.for to be hoisted with a
scf.if guard that checks against the trip count

This patch takes a step towards a less conservative LICM in MLIR as
discussed in the following discourse thread:

[Speculative LICM?](https://discourse.llvm.org/t/speculative-licm/80977)

This patch in particular does the following:

1. Relaxes the original constraint for hoisting that only hoists ops
without any side effects. This patch also allows the ops with only read
side effects to be hoisted into an scf.if guard only if every op in the
loop or its nested regions is side-effect free or has only read side
effects. This scf.if guard wraps the original scf.for and checks for
**trip_count > 0**.
2. To support this, two new interface methods are added to
**LoopLikeInterface**: _wrapInTripCountCheck_ and
_unwrapTripCountCheck_. Implementation starts with wrapping the scf.for
loop into scf.if guard using _wrapInTripCountCheck_ and if there is no
op hoisted into the this guard after we are done processing the
worklist, it unwraps the guard by calling _unwrapTripCountCheck_.

Using `LoopLikeOpInterface` as the basis for the implementation unifies
all the tiling logic for both `scf.for` and `scf.forall`. The only
difference is the actual loop generation. This is a follow up to
https://github.com/llvm/llvm-project/pull/72178
Instead of many entry points for each loop type, the loop type is now
passed as part of the options passed to the tiling method.

This is a breaking change with the following changes

1) The `scf::tileUsingSCFForOp` is renamed to `scf::tileUsingSCF`
2) The `scf::tileUsingSCFForallOp` is deprecated. The same
   functionality is obtained by using `scf::tileUsingSCF` and setting
   the loop type in `scf::SCFTilingOptions` passed into this method to
   `scf::SCFTilingOptions::LoopType::ForallOp` (using the
   `setLoopType` method).
3) The `scf::tileConsumerAndFusedProducerGreedilyUsingSCFForOp` is
   renamed to `scf::tileConsumerAndFuseProducerUsingSCF`. The use of
   the `controlFn` in `scf::SCFTileAndFuseOptions` allows implementing
   any strategy with the default callback implemeting the greedy fusion.
4) The `scf::SCFTilingResult` and `scf::SCFTileAndFuseResult` now use
   `SmallVector<LoopLikeOpInterface>`.
5) To make `scf::ForallOp` implement the parts of
   `LoopLikeOpInterface` needed, the `getOutputBlockArguments()`
   method is replaced with `getRegionIterArgs()`

These changes now bring the tiling and fusion capabilities using
`scf.forall` on par with what was already supported by `scf.for`

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.

Add a transform op for loop-invariant subset hoisting. Delete the old
transform op from the Linalg dialect.

Improve the bypass analysis for loop-like ops. Until now, loop-like ops
were treated like any other non-subset ops: they prevent hoisting of any
sort because the analysis does not know which parts of a tensor init
operand are accessed by the loop-like op. With this change, the analysis
can look into loop-like ops and analyze which subset they are operating
on.