[PATCH] Turn on -Wfree-labels by default if available

[Joseph Myers]

This breaks the build for Hurd (with compilers that support 
-Wfree-labels).  hurd/intr-msg.c contains a label on a declaration:

                    case MACH_MSG_TYPE_MOVE_SEND:
                      mach_port_t *ports = (mach_port_t *) data;

-- 
Joseph S. Myers
josmyers@redhat.com