Fix aliases on AIX

[Jan Hubicka]

Hi,
this patch fixes the devirt10 and devirt15 failures - the problem was that we did not look into alias target
when estimating devirt benefit.

Bootstrapped/regtested rs6000-aix, comitted.

	* ipa-cp.c (devirtualization_time_bonus): Walk through aliases.
	* ipa-inline-analysis.c (estimate_edge_devirt_benefit): Likewise.
Index: ipa-cp.c
===================================================================
--- ipa-cp.c	(revision 212394)
+++ ipa-cp.c	(working copy)
@@ -1671,6 +1671,7 @@
     {
       struct cgraph_node *callee;
       struct inline_summary *isummary;
+      enum availability avail;
       tree target;
 
       target = ipa_get_indirect_edge_target (ie, known_csts, known_binfos,
@@ -1683,6 +1684,9 @@
       callee = cgraph_get_node (target);
       if (!callee || !callee->definition)
 	continue;
+      callee = cgraph_function_node (callee, &avail);
+      if (avail < AVAIL_AVAILABLE)
+	continue;
       isummary = inline_summary (callee);
       if (!isummary->inlinable)
 	continue;
Index: ipa-inline-analysis.c
===================================================================
--- ipa-inline-analysis.c	(revision 212394)
+++ ipa-inline-analysis.c	(working copy)
@@ -2971,6 +2971,7 @@
   tree target;
   struct cgraph_node *callee;
   struct inline_summary *isummary;
+  enum availability avail;
 
   if (!known_vals.exists () && !known_binfos.exists ())
     return false;
@@ -2991,6 +2992,9 @@
   callee = cgraph_get_node (target);
   if (!callee || !callee->definition)
     return false;
+  callee = cgraph_function_node (callee, &avail);
+  if (avail < AVAIL_AVAILABLE)
+    return false;
   isummary = inline_summary (callee);
   return isummary->inlinable;
 }