[Bug driver/85165] gcc (and g++) not complaining about few unknown file extensions like *.CC, *.Cc, *.cC

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85165

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I suspect this is a difference between windows and linux and due to case
insensitivity rather than a difference in newer versions of GCC.