[mlir][vector] Group re-order patterns together (#102856)

Group all patterns that re-order vector.transpose and vector.broadcast
Ops (*) under `populateSinkVectorOpsPatterns`. These patterns are
normally used to "sink" redundant Vector Ops, hence grouping together.
Example:

```mlir
%at = vector.transpose %a, [1, 0]: vector<4x2xf32> to vector<2x4xf32>
%bt = vector.transpose %b, [1, 0]: vector<4x2xf32> to vector<2x4xf32>
%r = arith.addf %at, %bt : vector<2x4xf32>
```
would get converted to:
```mlir
%0 = arith.addf %a, %b : vector<4x2xf32>
%r = vector.transpose %0, [1, 0] : vector<2x4xf32>
```

This patch also moves all tests for these patterns so that all of them
are:
  * run under one test-flag: `test-vector-sink-patterns`,
  * located in one file: "vector-sink.mlir".

To facilitate this change:
  * `-test-sink-vector-broadcast` is renamed as
    `test-vector-sink-patterns`,
  * "sink-vector-broadcast.mlir" is renamed as "vector-sink.mlir",
  * tests for `ReorderCastOpsOnBroadcast` and
    `ReorderElementwiseOpsOnTranspose` patterns are moved from
    "vector-reduce-to-contract.mlir" to "vector-sink.mlir",
  * `ReorderElementwiseOpsOnTranspose` patterns are removed from
    `populateVectorReductionToContractPatterns` and added to (newly
    created) `populateSinkVectorOpsPatterns`,
  * `ReorderCastOpsOnBroadcast` patterns are removed from
    `populateVectorReductionToContractPatterns` - these are already
    present in `populateSinkVectorOpsPatterns`.

This should allow us better layering and more straightforward testing.
For the latter, the goal is to be able to easily identify which pattern
a particular test is exercising (especially when it's a specific
pattern).

NOTES FOR DOWNSTREAM USERS

In order to preserve the current functionality, please make sure to add
  * `populateSinkVectorOpsPatterns`,

wherever you are using `populateVectorReductionToContractPatterns`.
Also, rename `populateSinkVectorBroadcastPatterns` as
`populateSinkVectorOpsPatterns`.

(*) I didn't notice any other re-order patterns.

0 files changed, 0 insertions, 0 deletions