[SYCL][E2E] Add test for device image dependencies without host reference

sycl/test-e2e/DeviceImageDependencies/dynamic_link_opt_win.cpp

@@ -0,0 +1,42 @@
+// Test that device image dependencies from a DLL are not dropped when the
+// application is built at higher optimization levels on Windows.
+//
+// The bug: at /O2 the linker sees that no host symbol from the DLL is
+// referenced and drops the DLL import, which prevents the SYCL runtime
+// from discovering the device image in the DLL.
+
+// REQUIRES: windows
+
+// Build the DLL using the existing input:
+// RUN: %clangxx -fsycl -fsycl-allow-device-image-dependencies -DMAKE_DLL -O2 %shared_lib %S/Inputs/d.cpp -o %t_d.dll
+
+// Build app at -O0 — should work:
+// RUN: %clangxx -fsycl -fsycl-allow-device-image-dependencies %O0 %s %t_d.lib -o %t_O0.exe
+// RUN: %{run} %t_O0.exe
+
+// Build app at -O2 — fails due to the bug (DLL import dropped):
+// RUN: %clangxx -fsycl -fsycl-allow-device-image-dependencies -O2 %s %t_d.lib -o %t_O2.exe
+// RUN: %{run} %t_O2.exe
+
+// XFAIL: windows && run-mode
+// XFAIL-TRACKER: CMPLRLLVM-76054
+
+#include <cassert>
+#include <sycl/sycl.hpp>
+
+// No __declspec(dllimport) — only a device-side dependency on the DLL.
+SYCL_EXTERNAL int levelD(int val);
+
+int main() {
+  int result = 0;
+  {
+    sycl::queue q;
+    int *d = sycl::malloc_device<int>(1, q);
+    q.single_task([=] { *d = levelD(0); }).wait();
+    q.memcpy(&result, d, sizeof(int)).wait();
+    sycl::free(d, q);
+  }
+  // Device path of levelD: val |= (0xD << 12) => 0xD000
+  assert(result == 0xD000);
+  return 0;
+}