[gnutls-help] mkstemp mingw x86_64 failure

[Roger Pack]

As a note, gnutls cross compiler ok i386 [mingw-w64] however with x86_64

CCLD danetool.exe
danetool.o:danetool.c:(.text+0x1266): undefined reference to `mkstemp'
collect2: error: ld returned 1 exit status

Unless you feel this is something that mingw-w64 out to "just provide"
or what not. Kind of weird that it succeeds in i386.

Cheers!
-roger-