C++: Support more function types

cpp/ql/lib/semmlecode.cpp.dbscheme

@@ -356,6 +356,8 @@ case @function.kind of
 | 4 = @conversion_function
 | 5 = @operator
 | 6 = @builtin_function     // GCC built-in functions, e.g. __builtin___memcpy_chk
+| 7 = @user_defined_literal
+| 8 = @deduction_guide
 ;
 */