fix more comments

Signed-off-by: Tikhomirova, Kseniya <kseniya.tikhomirova@intel.com>

Author: KseniyaTikhomirova

libsycl/include/sycl/__impl/detail/macro_definitions.hpp

@@ -35,9 +35,9 @@ static_assert(__cplusplus >= 201703L, "Libsycl requires C++17 or later.");
 // when linking to a release build of libsycl and with the /MDd option when
 // linking to a debug build.
 #  define ERROR_MESSAGE                                                        \
-    "Libsycl is designed to work safely with dynamic C++ runtime."             \
-    "Please use /MD switch with sycl.dll, /MDd switch with sycld.dll, "        \
-    "or -fsycl switch to set C++ runtime automatically."
+    "Libsycl requires use of a DLL version of the MSVC RT library. "           \
+    "Please use /MD to link with a release build of libsycl or /MDd to link"   \
+    " with a debug build."
 #  if defined(_MSC_VER)
 #    pragma message(ERROR_MESSAGE)
 #  else

libsycl/include/sycl/__impl/detail/obj_utils.hpp

@@ -65,8 +65,12 @@ SyclObject createSyclObjFromImpl(From &&from) {
 template <typename T> struct HashBase {
   size_t operator()(const T &Obj) const {
 #ifdef __SYCL_DEVICE_ONLY__
+#  if __has_builtin(__builtin_unreachable)
+    __builtin_unreachable()
+#  else
     (void)Obj;
     return 0;
+#  endif
 #else
     auto &Impl = sycl::detail::getSyclObjImpl(Obj);
     return std::hash<std::decay_t<decltype(Impl)>>{}(Impl);