[Bug c/88568] [7/8/9 Regression] 'dllimport' no longer implies 'extern' in C

[10walls at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88568

--- Comment #8 from jon_y <10walls at gmail dot com> ---
I've used a linux hosted mingw toolchain to build a mingw toolchain from the
same sources, it seems to be working fine.

I've only enabled C and C++.