gdb: make add_com_alias accept target as a cmd_list_element

The alias creation functions currently accept a name to specify the
target command.  They pass this to add_alias_cmd, which needs to lookup
the target command by name.

Given that:

 - We don't support creating an alias for a command before that command
   exists.
 - We always use add_info_alias just after creating that target command,
   and therefore have access to the target command's cmd_list_element.

... change add_com_alias to accept the target command as a
cmd_list_element (other functions are done in subsequent patches).  This
ensures we don't create the alias before the target command, because you
need to get the cmd_list_element from somewhere when you call the alias
creation function.  And it avoids an unecessary command lookup.  So it
seems better to me in every aspect.

gdb/ChangeLog:

	* command.h (add_com_alias): Accept target as
	cmd_list_element.  Update callers.

Change-Id: I24bed7da57221cc77606034de3023fedac015150

1 files changed, 5 insertions, 4 deletions

diff --git a/gdb/regcache.c b/gdb/regcache.c
index 51e9eff..2d50f3e 100644
--- a/gdb/regcache.c
+++ b/gdb/regcache.c
@@ -2092,10 +2092,11 @@ _initialize_regcache ()
   gdb::observers::thread_ptid_changed.attach (regcache_thread_ptid_changed,
 					      "regcache");
 
-  add_cmd ("register-cache", class_maintenance, reg_flush_command,
-	   _("Force gdb to flush its register and frame cache."),
-	   &maintenanceflushlist);
-  c = add_com_alias ("flushregs", "maintenance flush register-cache",
+  cmd_list_element *maintenance_flush_register_cache_cmd
+    = add_cmd ("register-cache", class_maintenance, reg_flush_command,
+	       _("Force gdb to flush its register and frame cache."),
+	       &maintenanceflushlist);
+  c = add_com_alias ("flushregs", maintenance_flush_register_cache_cmd,
 		     class_maintenance, 0);
   deprecate_cmd (c, "maintenance flush register-cache");