Empty LTO partition fix

[Jan Hubicka <hubicka@ucw.cz>]

Hi,
the empty partitions gets created when node gets assigned to earlier
partition.  This happens for thunks, aliases and partitioned comdats.
Hope this will fix all occurences of the problem.

Bootstrapped/regtested x86_64-linux

Honza

	PR lto/23754
	* lto.c (lto_1_to_1_map): Don't create empty partitions.
	(lto_balanced_map): Likewise.

Index: lto.c
===================================================================
*** lto.c	(revision 175166)
--- lto.c	(working copy)
*************** lto_1_to_1_map (void)
*** 1516,1522 ****
  
    for (node = cgraph_nodes; node; node = node->next)
      {
!       if (!partition_cgraph_node_p (node))
  	continue;
  
        file_data = node->local.lto_file_data;
--- 1516,1523 ----
  
    for (node = cgraph_nodes; node; node = node->next)
      {
!       if (!partition_cgraph_node_p (node)
! 	  || node->aux)
  	continue;
  
        file_data = node->local.lto_file_data;
*************** lto_1_to_1_map (void)
*** 1545,1557 ****
  	  npartitions++;
  	}
  
!       if (!node->aux)
!         add_cgraph_node_to_partition (partition, node);
      }
  
    for (vnode = varpool_nodes; vnode; vnode = vnode->next)
      {
!       if (!partition_varpool_node_p (vnode))
  	continue;
        file_data = vnode->lto_file_data;
        slot = pointer_map_contains (pmap, file_data);
--- 1546,1558 ----
  	  npartitions++;
  	}
  
!       add_cgraph_node_to_partition (partition, node);
      }
  
    for (vnode = varpool_nodes; vnode; vnode = vnode->next)
      {
!       if (!partition_varpool_node_p (vnode)
! 	  || vnode->aux)
  	continue;
        file_data = vnode->lto_file_data;
        slot = pointer_map_contains (pmap, file_data);
*************** lto_1_to_1_map (void)
*** 1565,1572 ****
  	  npartitions++;
  	}
  
!       if (!vnode->aux)
!         add_varpool_node_to_partition (partition, vnode);
      }
    for (node = cgraph_nodes; node; node = node->next)
      node->aux = NULL;
--- 1566,1572 ----
  	  npartitions++;
  	}
  
!       add_varpool_node_to_partition (partition, vnode);
      }
    for (node = cgraph_nodes; node; node = node->next)
      node->aux = NULL;
*************** lto_balanced_map (void)
*** 1675,1682 ****
  
    for (i = 0; i < n_nodes; i++)
      {
!       if (!order[i]->aux)
!         add_cgraph_node_to_partition (partition, order[i]);
        total_size -= inline_summary (order[i])->size;
  
        /* Once we added a new node to the partition, we also want to add
--- 1675,1683 ----
  
    for (i = 0; i < n_nodes; i++)
      {
!       if (order[i]->aux)
! 	continue;
!       add_cgraph_node_to_partition (partition, order[i]);
        total_size -= inline_summary (order[i])->size;
  
        /* Once we added a new node to the partition, we also want to add
*************** lto_balanced_map (void)
*** 1856,1861 ****
--- 1857,1864 ----
  	    }
  	  i = best_i;
   	  /* When we are finished, avoid creating empty partition.  */
+ 	  while (i < n_nodes - 1 && order[i + 1]->aux)
+ 	    i++;
  	  if (i == n_nodes - 1)
  	    break;
  	  partition = new_partition ("");