time_r module does not work on MingW

[Christian Biesinger]

Hello!

I tried to use the time_r module with GDB (using Gnulib revision 38237baf99386101934cd93278023aa4ae523ec0)

However, I found that it does not compile, see logs at:

https://gdb-buildbot.osci.io/#/builders/23/builds/934

Apparently, the MingW time.h has localtime_r and gmtime_r defined as __forceinline functions outside of the extern "C" block, so they use C++ linkage, whereas gnulib expects C linkage.

I'm not sure what the best fix is but this seems unfortunate?

Christian