[SYCL] Align execution_capability info with spec (#16673)

Aligns behavior with
https://github.com/KhronosGroup/SYCL-Docs/pull/625/files
Test update to pair it with:
KhronosGroup/SYCL-CTS#1020

Done in RT for simplicity. 
Since execution_capability is marked as deprecated I would suggest to
make update in UR & UR adapters after it is completely removed.

---------

Signed-off-by: Tikhomirova, Kseniya <[email protected]>

Author: KseniyaTikhomirova

sycl/source/detail/device_info.hpp

@@ -359,6 +359,11 @@ template <>
 struct get_device_info_impl<std::vector<info::execution_capability>,
                             info::device::execution_capabilities> {
   static std::vector<info::execution_capability> get(const DeviceImplPtr &Dev) {
+    if (Dev->getBackend() != backend::opencl)
+      throw exception(make_error_code(errc::invalid),
+                      "info::device::execution_capabilities is available for "
+                      "backend::opencl only");
+
     ur_device_exec_capability_flag_t result;
     Dev->getAdapter()->call<UrApiKind::urDeviceGetInfo>(
         Dev->getHandleRef(),

sycl/test-e2e/Basic/info.cpp

@@ -313,9 +313,17 @@ int main() {
       dev, "Is compiler available");
   print_info<info::device::is_linker_available, bool>(dev,
                                                       "Is linker available");
-  print_info<info::device::execution_capabilities,
-             std::vector<info::execution_capability>>(dev,
-                                                      "Execution capabilities");
+  try {
+    print_info<info::device::execution_capabilities,
+               std::vector<info::execution_capability>>(
+        dev, "Execution capabilities");
+    assert(backend == sycl::backend::opencl &&
+           "An exception is expected for non OpenCL backend");
+  } catch (const sycl::exception &e) {
+    assert(e.code() == sycl::errc::invalid &&
+           backend != sycl::backend::opencl && "Unexpected exception");
+  }
+
   print_info<info::device::queue_profiling, bool>(dev, "Queue profiling");
   print_info<info::device::built_in_kernels, std::vector<std::string>>(
       dev, "Built in kernels");