[SYCL] Add test for private array init by zeroes (#1402)

Test checks that SYCL program is not crashed if it contains
a class/struct that has private array member which is initialized
by zeroes.

Signed-off-by: Mikhail Lychkov <mikhail.lychkov@intel.com>

Author: mlychkov

sycl/test/regression/private_array_init_test.cpp

@@ -0,0 +1,50 @@
+// RUN: %clangxx -fsycl %s -o %t.out -lOpenCL
+
+// RUN: %CPU_RUN_PLACEHOLDER %t.out
+// RUN: %GPU_RUN_PLACEHOLDER %t.out
+// RUN: %ACC_RUN_PLACEHOLDER %t.out
+
+//==- private_array_init_test.cpp - Regression test for private array init -==//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include <CL/sycl.hpp>
+
+namespace s = cl::sycl;
+
+class A {
+public:
+  A() : _arr{0, 0, 0} {}
+
+  size_t size() {
+    return sizeof(_arr) / sizeof(_arr[0]);
+  }
+
+private:
+  size_t _arr[3];
+};
+
+int main() {
+  size_t data = 1;
+
+  s::queue q;
+  {
+    s::buffer<size_t, 1> buf(&data, s::range<1>(1));
+    q.submit([&](s::handler &cgh) {
+      auto acc = buf.get_access<s::access::mode::read_write>(cgh);
+      cgh.single_task<class test>([=]() {
+        // Test that SYCL program is not crashed if it contains a class/struct
+        // that has private array member which is initialized by zeroes.
+        acc[0] += A().size();
+      });
+    });
+  }
+
+  assert(data == 4);
+
+  return 0;
+}