Add test for static device global

Make sure that static device globals work.

Author: hdelan

sycl/test-e2e/DeviceGlobal/device_global_static.cpp

@@ -0,0 +1,32 @@
+// RUN: %{build} -o %t.out
+// RUN: %{run} %t.out
+//
+// The OpenCL GPU backends do not currently support device_global backend
+// calls.
+// UNSUPPORTED: opencl && gpu
+//
+// Tests basic device_global access through device kernels.
+
+#include "common.hpp"
+
+static device_global<int[4], TestProperties> DeviceGlobalVar;
+
+int main() {
+  queue Q;
+
+  Q.single_task([=]() { DeviceGlobalVar.get()[0] = 42; });
+  // Make sure that the write happens before subsequent read
+  Q.wait();
+
+  int OutVal = 0;
+  {
+    buffer<int, 1> OutBuf(&OutVal, 1);
+    Q.submit([&](handler &CGH) {
+      auto OutAcc = OutBuf.get_access<access::mode::write>(CGH);
+      CGH.single_task([=]() { OutAcc[0] = DeviceGlobalVar.get()[0]; });
+    });
+  }
+  assert(OutVal == 42 && "Read value does not match.");
+  return 0;
+}
+