libgfortran and libiberty: mkstemp in gfortran/io/unix.c

[Aaron W. LaFramboise]

MinGW does not have mkstemp, used in gfortran/io/unix.c.

libiberty does provide a mkstemps function, which is almost the same
thing, except it has support for a suffix.  However, there doesn't
appear to be a prototype anywhere for it, but I think it should, since
it is not a replacement function (...is it?).  Should a prototype be
added to include/libiberty.h for it?

And, should unix.c be using it instead of mkstemp, which libiberty does
not seem to provide?  Or maybe libiberty should provide a mkstemp?

Aaron W. LaFramboise