xenperf: name "newer" hypercalls

xenperf: name "newer" hypercalls

This table must not have got updated in quite a while; tmem_op for
example has managed to not only appear since then, but also disappear
again (adding a name for it nevertheless, to make more obvious that
something strange is going on if the slot would ever have a non-zero
value).

Also resolve arch_0 and arch_1 to more meaningful names on x86.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>