c++: Consistently expose singleton overloads

[Nathan Sidwell]

This is a patch from my name-lookup overhaul.  I noticed the parser
and one path in name-lookup looked through an overload of a single
known decl.  It seems more consistent to do that in both paths through
name-lookup, and not in the parser itself.

        gcc/cp/
        * name-lookup.c (lookup_qualified_name): Expose an overload of a
        singleton with known type.
        (lookup_name_1): Just check the overload's type to expose it.
        * parser.c (cp_parser_lookup_name): Do not do that check here.

pushing to trunk

nathan

--
Nathan Sidwell

diff --git i/gcc/cp/name-lookup.c w/gcc/cp/name-lookup.c
index 5bda4c2eea9..16efd161301 100644
--- i/gcc/cp/name-lookup.c
+++ w/gcc/cp/name-lookup.c
@@ -5885,7 +5885,14 @@ lookup_qualified_name (tree scope, tree name, LOOK_want want, bool complain)
       name_lookup lookup (name, want);
 
       if (qualified_namespace_lookup (scope, &lookup))
-	t = lookup.value;
+	{
+	  t = lookup.value;
+
+	  /* If we have a known type overload, pull it out.  This can happen
+	     for using decls.  */
+	  if (TREE_CODE (t) == OVERLOAD && TREE_TYPE (t) != unknown_type_node)
+	    t = OVL_FUNCTION (t);
+	}
     }
   else if (cxx_dialect != cxx98 && TREE_CODE (scope) == ENUMERAL_TYPE)
     t = lookup_enumerator (scope, name);
@@ -6515,8 +6522,9 @@ lookup_name_1 (tree name, LOOK_where where, LOOK_want want)
 
  found:;
 
-  /* If we have a single function from a using decl, pull it out.  */
-  if (val && TREE_CODE (val) == OVERLOAD && !really_overloaded_fn (val))
+  /* If we have a known type overload, pull it out.  This can happen
+     for both using decls and unhidden functions.  */
+  if (val && TREE_CODE (val) == OVERLOAD && TREE_TYPE (val) != unknown_type_node)
     val = OVL_FUNCTION (val);
 
   return val;
diff --git i/gcc/cp/parser.c w/gcc/cp/parser.c
index 6e7b982f073..9e3c67c6d15 100644
--- i/gcc/cp/parser.c
+++ w/gcc/cp/parser.c
@@ -28633,11 +28633,6 @@ cp_parser_lookup_name (cp_parser *parser, tree name,
 					  prefer_type_arg (tag_type),
 					  /*complain=*/true);
 
-	  /* If we have a single function from a using decl, pull it out.  */
-	  if (TREE_CODE (decl) == OVERLOAD
-	      && !really_overloaded_fn (decl))
-	    decl = OVL_FUNCTION (decl);
-
 	  if (pushed_scope)
 	    pop_scope (pushed_scope);
 	}