[mlir][Linalg] Unrestrict redundant transfer hoisting from func.func (#79516)

All the hoistRedundantVectorTransfers op does is walk the target
operation, which does not have to be restricted to func.func.

Author: qedawkins

mlir/include/mlir/Dialect/Linalg/Transforms/Hoisting.h

@@ -10,10 +10,8 @@
 #define MLIR_DIALECT_LINALG_TRANSFORMS_HOISTING_H_
 
 namespace mlir {
+class Operation;
 class RewriterBase;
-namespace func {
-class FuncOp;
-} // namespace func
 namespace scf {
 class ForOp;
 } // namespace scf
@@ -43,7 +41,7 @@ namespace linalg {
 ///
 /// WARNING: This hoisting does not model parallelism and is generally incorrect
 /// when used on distributed loops with memref semantics!
-void hoistRedundantVectorTransfers(func::FuncOp func);
+void hoistRedundantVectorTransfers(Operation *root);
 
 } // namespace linalg
 } // namespace mlir

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

@@ -73,16 +73,16 @@ static bool noAliasingUseInLoop(vector::TransferReadOp transferRead,
   return true;
 }
 
-void mlir::linalg::hoistRedundantVectorTransfers(func::FuncOp func) {
+void mlir::linalg::hoistRedundantVectorTransfers(Operation *root) {
   bool changed = true;
   while (changed) {
     changed = false;
     // First move loop invariant ops outside of their loop. This needs to be
     // done before as we cannot move ops without interrupting the function walk.
-    func.walk(
+    root->walk(
         [&](LoopLikeOpInterface loopLike) { moveLoopInvariantCode(loopLike); });
 
-    func.walk([&](vector::TransferReadOp transferRead) {
+    root->walk([&](vector::TransferReadOp transferRead) {
       if (!isa<MemRefType>(transferRead.getShapedType()))
         return WalkResult::advance();