Add clarifying comment to hopefully prevent accidental revert of the …

…patch

sycl/include/sycl/handler.hpp

@@ -1046,6 +1046,11 @@ class __SYCL_EXPORT handler {
   /// Process kernel properties.
   ///
   /// Stores information about kernel properties into the handler.
+  ///
+  /// Note: it is important that this function *does not* depend on kernel
+  /// name or kernel type, because then it will be instantiated for every
+  /// kernel, even though body of those instantiated functions could be almost
+  /// the same, thus unnecessary increasing compilation time.
   template <
       bool IsESIMDKernel,
       typename PropertiesT = ext::oneapi::experimental::empty_properties_t>