When using the MinGW toolchain, we use the .exe suffix for the
executable name. We also need to use it for the symlinks in the
build directory.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20211109144504.1541206-1-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>