Daniel,

The new xml features support introduced a gdbserver crash when the target
doesn't implement the target_ops->arch_string method.  win32-i386-low is 
one example.
This patch gets me going.

Ok?

Cheers,
Pedro Alves

---
gdb/gdbserver/ChangeLog:

   * server.c (get_features_xml): Check if target implemented arch_string.
   * win32-i386-low.c (win32_arch_string): New.
    (win32_target_ops): Add win32_arch_string as arch_string member.