symbols: Generate an xen-sym.map

You could construct _most_ of the names of the functions
by doing 'nm --defined' but unfortunatly you do not get the
<file> prefix that is added on in Xen . For example:

$ cat xen-syms.symbols |grep do_domain_pause
0xffff82d080104920 t domain.c#do_domain_pause
$ nm --defined xen-syms|grep do_domain_pause
ffff82d080104920 t do_domain_pause

This is normally not an issue, but if one is doing livepatching and
wants during build-time verify that the symbols the livepatch payloads
will patch do correspond to the one the hypervisor has built - this helps a lot.

Note that during runtime one can do:
[root@localhost xen]# cat /proc/xen/xensyms |grep do_domain_pause
ffff82d080104920 t domain.c#do_domain_pause

But one may not want to build and verify a livepatch on the same host.

Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

.gitignore

@@ -273,6 +273,7 @@ tools/flask/policy/policy.conf
 tools/flask/policy/xenpolicy-*
 xen/xen
 xen/xen-syms
+xen/xen-syms.map
 xen/xen.*
 unmodified_drivers/linux-2.6/.tmp_versions
 unmodified_drivers/linux-2.6/*.cmd