[Bug c/91980] No diagnostic for type "complex"

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91980

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I think the problem is the define for complex is in a system header which
causes the error not to happen due to -Wno-system-headers being the default.
This is a known issue in newer versions of GCC.  There might be another bug for
the similar issue.