[MLIR][Tensor] Add custom builder for unpack op

mlir/include/mlir/Dialect/Tensor/IR/TensorOps.td

let assemblyFormat = [{
     $source
     (`outer_dims_perm` `=` $outer_dims_perm^)?
     `inner_dims_pos` `=` $inner_dims_pos
     `inner_tiles` `=`
     custom<DynamicIndexList>($inner_tiles, $static_inner_tiles)
     `into` $dest attr-dict `:` type($source) `->` type($dest)
   }];
 
+  let builders = [
+    OpBuilder<(ins "Value":$source, "Value":$dest,
+    "ArrayRef<int64_t>":$innerDimsPos,
+    "ArrayRef<OpFoldResult>":$innerTiles,
+    CArg<"ArrayRef<int64_t>", "{}">:$outerDimsPerm)>
+  ];
+
   let extraClassDeclaration = commonExtraClassDeclaration;
   let hasCanonicalizeMethod = 1;
 }
 
 //===----------------------------------------------------------------------===//
 // YieldOp
 //===----------------------------------------------------------------------===//
 

mlir/lib/Dialect/Tensor/IR/TensorOps.cpp

 Speculation::Speculatability UnPackOp::getSpeculatability() {
   // See PackOp::getSpeculatability.
   if (!areTilesAndTiledDimsAllConstant(*this))
     return Speculation::NotSpeculatable;
 
   return Speculation::Speculatable;
 }
 
+void UnPackOp::build(OpBuilder &builder, OperationState &state, Value source,
+                     Value dest, ArrayRef<int64_t> innerDimsPos,
+                     ArrayRef<OpFoldResult> innerTiles,
+                     ArrayRef<int64_t> outerDimsPerm) {
+  assert(innerDimsPos.size() == innerTiles.size() &&
+         "number of tile sizes specified must match the specified number of "
+         "original dimensions to be tiled");
+  SmallVector<int64_t> staticTileSizes;
+  SmallVector<Value> dynamicTileSizes;
+  dispatchIndexOpFoldResults(innerTiles, dynamicTileSizes, staticTileSizes,
+                             ShapedType::kDynamic);
+  build(builder, state, dest.getType(), source, dest,
+        outerDimsPerm.empty() ? nullptr
+                              : builder.getDenseI64ArrayAttr(outerDimsPerm),
+        builder.getDenseI64ArrayAttr(innerDimsPos), dynamicTileSizes,
+        builder.getDenseI64ArrayAttr(staticTileSizes));
+}
+
 /// pack(unpack(x)) -> x
 LogicalResult UnPackOp::canonicalize(UnPackOp unpackOp,
                                      PatternRewriter &rewriter) {
   PackOp packOp = unpackOp.getSource().getDefiningOp<tensor::PackOp>();
   if (!packOp || packOp.getDestType() != unpackOp.getSourceType())
     return failure();
   if (packOp.getInnerDimsPos() != unpackOp.getInnerDimsPos())
     return failure();