Flip Identifier to StringAttr

In preparation of upstream flip.

PiperOrigin-RevId: 419833214

iree/compiler/Codegen/SPIRV/Utils.cpp

diff --git a/iree/compiler/Codegen/SPIRV/Utils.cpp b/iree/compiler/Codegen/SPIRV/Utils.cpp
index 9eda38f..bf83338 100644
--- a/iree/compiler/Codegen/SPIRV/Utils.cpp
+++ b/iree/compiler/Codegen/SPIRV/Utils.cpp
@@ -21,7 +21,6 @@
 #include "mlir/Dialect/MemRef/IR/MemRef.h"
 #include "mlir/Dialect/SPIRV/IR/TargetAndABI.h"
 #include "mlir/IR/BuiltinOps.h"
-#include "mlir/IR/Identifier.h"
 #include "mlir/IR/Matchers.h"
 #include "mlir/IR/Region.h"
 #include "mlir/Support/LogicalResult.h"

iree/compiler/Dialect/HAL/IR/HALTypes.cpp

diff --git a/iree/compiler/Dialect/HAL/IR/HALTypes.cpp b/iree/compiler/Dialect/HAL/IR/HALTypes.cpp
index 7476f81..cf81053 100644
--- a/iree/compiler/Dialect/HAL/IR/HALTypes.cpp
+++ b/iree/compiler/Dialect/HAL/IR/HALTypes.cpp
@@ -482,7 +482,7 @@
 // static
 SmallVector<IREE::HAL::DeviceTargetAttr, 4> DeviceTargetAttr::lookup(
     Operation *op) {
-  auto attrId = mlir::Identifier::get("hal.device.targets", op->getContext());
+  auto attrId = mlir::StringAttr::get(op->getContext(), "hal.device.targets");
   while (op) {
     auto targetsAttr = op->getAttrOfType<ArrayAttr>(attrId);
     if (targetsAttr) {

iree/compiler/Dialect/Vulkan/IR/VulkanAttributes.cpp

diff --git a/iree/compiler/Dialect/Vulkan/IR/VulkanAttributes.cpp b/iree/compiler/Dialect/Vulkan/IR/VulkanAttributes.cpp
index 70fe082..cad23d6 100644
--- a/iree/compiler/Dialect/Vulkan/IR/VulkanAttributes.cpp
+++ b/iree/compiler/Dialect/Vulkan/IR/VulkanAttributes.cpp
@@ -12,7 +12,6 @@
 #include "mlir/IR/Builders.h"
 #include "mlir/IR/BuiltinTypes.h"
 #include "mlir/IR/Diagnostics.h"
-#include "mlir/IR/Identifier.h"
 #include "mlir/IR/Location.h"
 
 namespace mlir {