ipa/94947 - avoid using externally_visible_p ()

externally_visible_p wasn't the correct predicate to use (even if it
worked), instead we should use DECL_EXTERNAL || TREE_PUBLIC.

2020-05-07  Richard Biener  <rguenther@suse.de>

	PR ipa/94947
	* tree-ssa-structalias.c (refered_from_nonlocal_fn): Use
	DECL_EXTERNAL || TREE_PUBLIC instead of externally_visible.
	(refered_from_nonlocal_var): Likewise.
	(ipa_pta_execute): Likewise.

gcc/ChangeLog

 2020-05-12  Richard Biener  <rguenther@suse.de>
 
 	Backport from mainline
+	2020-05-07  Richard Biener  <rguenther@suse.de>
+
+	PR ipa/94947
+	* tree-ssa-structalias.c (refered_from_nonlocal_fn): Use
+	DECL_EXTERNAL || TREE_PUBLIC instead of externally_visible.
+	(refered_from_nonlocal_var): Likewise.
+	(ipa_pta_execute): Likewise.
+
 	2020-05-05  Richard Biener  <rguenther@suse.de>
 
 	PR ipa/94947

gcc/tree-ssa-structalias.c

@@ -8085,7 +8085,8 @@ refered_from_nonlocal_fn (struct cgraph_node *node, void *data)
 {
   bool *nonlocal_p = (bool *)data;
   *nonlocal_p |= (node->used_from_other_partition
-		  || node->externally_visible
+		  || DECL_EXTERNAL (node->decl)
+		  || TREE_PUBLIC (node->decl)
 		  || node->force_output
 		  || lookup_attribute ("noipa", DECL_ATTRIBUTES (node->decl)));
   return false;
@@ -8097,7 +8098,8 @@ refered_from_nonlocal_var (struct varpool_node *node, void *data)
 {
   bool *nonlocal_p = (bool *)data;
   *nonlocal_p |= (node->used_from_other_partition
-		  || node->externally_visible_p ()
+		  || DECL_EXTERNAL (node->decl)
+		  || TREE_PUBLIC (node->decl)
 		  || node->force_output);
   return false;
 }
@@ -8146,7 +8148,8 @@ ipa_pta_execute (void)
 	 For local functions we see all callers and thus do not need initial
 	 constraints for parameters.  */
       bool nonlocal_p = (node->used_from_other_partition
-			 || node->externally_visible
+			 || DECL_EXTERNAL (node->decl)
+			 || TREE_PUBLIC (node->decl)
 			 || node->force_output
 			 || lookup_attribute ("noipa",
 					      DECL_ATTRIBUTES (node->decl)));
@@ -8187,7 +8190,8 @@ ipa_pta_execute (void)
 
       /* For the purpose of IPA PTA unit-local globals are not
          escape points.  */
-      bool nonlocal_p = (var->externally_visible_p ()
+      bool nonlocal_p = (DECL_EXTERNAL (var->decl)
+			 || TREE_PUBLIC (var->decl)
 			 || var->used_from_other_partition
 			 || var->force_output);
       var->call_for_symbol_and_aliases (refered_from_nonlocal_var,