[SYCL] Hotfix for SYCL unittests on host device (#4539)

Author: Alexander Batashev

sycl/unittests/Extensions/DefaultContext.cpp

@@ -26,6 +26,10 @@ TEST(DefaultContextTest, DefaultContextTest) {
                    SYCLConfig<SYCL_ENABLE_DEFAULT_CONTEXTS>::reset);
 
   sycl::platform Plt1{sycl::default_selector()};
+  if (Plt1.is_host()) {
+    std::cout << "Host platform does not support PI mock.\n";
+    return;
+  }
   sycl::unittest::PiMock Mock1{Plt1};
   setupDefaultMockAPIs(Mock1);
 
@@ -52,6 +56,10 @@ TEST(DefaultContextTest, DefaultContextCanBeDisabled) {
                    SYCLConfig<SYCL_ENABLE_DEFAULT_CONTEXTS>::reset);
 
   sycl::platform Plt{sycl::default_selector()};
+  if (Plt.is_host()) {
+    std::cout << "Host platform does not support PI mock.\n";
+    return;
+  }
   sycl::unittest::PiMock Mock{Plt};
   setupDefaultMockAPIs(Mock);