bug#51059: Latest master doesn't build on Win10

[Arash Esbati]

Hi all,

I updated my local repo to commit 444dfc044f and the build process (with
Msys2) breaks with:

  CC       json.o
  CC       tparam.o
  CC       lastfile.o
  CCLD     temacs.exe
Z:/path-to/bin/ld.exe: comp.o:comp.c:(.text+0x322): undefined reference to 
`md5_stream'
collect2.exe: error: ld returned 1 exit status
make[1]: *** [Makefile:647: temacs.exe] Error 1

My current working build is 947aee281c from master.  I suspect it has
something to do with commit 2dc88a27a4.  Is this Win only or also on
other platforms?

Best, Arash