GitLab

 nt/mingw-cfg.site (ac_cv_func_mkostemp): New var with value of "yes".
 nt/inc/ms-w32.h (mkostemp): Declare prototype.
 nt/config.nt (HAVE_MKOSTEMP): Define to 1.

 src/w32.c (mkostemp): New function.
 (mktemp): Remove, no longer used.  Most of the code reused in mkostemp.

Fixes: debbugs:15015