Merge topic 'bootstrap-intel' into release-3.18

796466284b bootstrap: Fix support for Intel compiler with modern GNU system compiler

Acked-by: Kitware Robot <[email protected]>
Merge-request: !5057

bootstrap

@@ -1181,7 +1181,7 @@ int check_cxx14()
 }
 #endif
 
-#if (__cplusplus >= 201703L || defined(__INTEL_COMPILER) && defined(__cpp_if_constexpr))
+#if (__cplusplus >= 201703L || defined(__INTEL_COMPILER) && defined(__cpp_deduction_guides))
 #include <optional>
 template <typename T,
           typename std::invoke_result<decltype(&T::get), T>::type = nullptr>