[MLIR][Linalg] Update filename to reflect implementation (NFC)

[mravishankar]

The name is confusing now. The pad op is fused with it's producer (not consumer). Could we either revert the change or rename it to FusePadOpWithLinalgProducer

[chelini]

In D128978#3625300, @mravishankar wrote:

The name is confusing now. The pad op is fused with it's producer (not consumer). Could we either revert the change or rename it to FusePadOpWithLinalgProducer

Updated. I went for FusePadOpWithLinalgProducer.

mlir/lib/Dialect/Linalg/Transforms/CMakeLists.txt

 add_mlir_dialect_library(MLIRLinalgTransforms
   BubbleUpExtractSlice.cpp
   BufferizableOpInterfaceImpl.cpp
   Bufferize.cpp
   CodegenStrategy.cpp
   ConstantFold.cpp
   Detensorize.cpp
   DropUnitDims.cpp
   ElementwiseOpFusion.cpp
   ElementwiseToLinalg.cpp
+  FusePadOpWithLinalgConsumer.cpp
   Fusion.cpp
   FusionOnTensors.cpp
   Generalization.cpp
   Hoisting.cpp
   HoistPadding.cpp
   InitTensorToAllocTensor.cpp
   InlineScalarOperands.cpp
   Interchange.cpp
   Loops.cpp
   LinalgStrategyPasses.cpp
   NamedOpConversions.cpp
-  PadOpInterchange.cpp
   Promotion.cpp
   SparseTensorRewriting.cpp
   SplitReduction.cpp
   Tiling.cpp
   TilingInterfaceImpl.cpp
   Transforms.cpp
   Vectorization.cpp
 

mlir/lib/Dialect/Linalg/Transforms/FusePadOpWithLinalgConsumer.cpp

-//===- PadOpInterchange.cpp - Interchange tensor.pad with linalg producer -===//
+//===- FusePadOpWithLinalgConsumer.cpp ---- Fuse pad with linalg producer -===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
-// This file implements patterns that intechanges a linalg.generic -> tensor.pad
-// op chain into a tensor.extract_slice -> linalg.generic -> tensor.insert_slice
+// This file implements patterns that fuses a linalg.generic -> tensor.pad op
+// chain into a tensor.extract_slice -> linalg.generic -> tensor.insert_slice
 // op chain.
 //
 //===----------------------------------------------------------------------===//
 
 #include "mlir/Dialect/Linalg/Transforms/Transforms.h"
 
 #include "mlir/Dialect/Linalg/IR/Linalg.h"
 #include "mlir/Transforms/GreedyPatternRewriteDriver.h"