Update ort_model_only_test.cc

Fix for undeclared identifier linker error

Author: orlmon01

onnxruntime/test/framework/ort_model_only_test.cc

@@ -24,6 +24,8 @@
 
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
+#define WIDEN2(x) L##x
+#define WIDEN(x) WIDEN2(x)
 
 using namespace ONNX_NAMESPACE;
 
@@ -41,7 +43,7 @@ std::filesystem::path ResolveTestPath(const std::filesystem::path& path) {
   }
 
   static const std::filesystem::path kSourceTestRoot =
-      std::filesystem::path{ORT_TSTR(__FILE__)}.parent_path().parent_path();
+    std::filesystem::path{WIDEN(__FILE__)}.parent_path().parent_path();
   std::filesystem::path source_candidate = kSourceTestRoot / path;
   if (std::filesystem::exists(source_candidate)) {
     return source_candidate;