After this patch contrib/elf2dmp can be built for Windows x86 and x86_64
hosts by mingw.

Signed-off-by: Viktor Prutyanov <viktor.prutyanov@phystech.edu>
Message-Id: <20181220012441.13694-7-viktor.prutyanov@phystech.edu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>