[gcc-in-cxx] fix tree-into-ssa.c for C++

[Thomas Neumann]

The patch corrects enum usage for tree-into-ssa.c. Ok to commit?

Thomas

* tree-into-ssa.c (get_ssa_name_ann): Use NEED_PHI_STATE_UNKNOWN instead of 
0

Index: gcc/tree-into-ssa.c
===================================================================
--- gcc/tree-into-ssa.c	(revision 144245)
+++ gcc/tree-into-ssa.c	(working copy)
@@ -325,7 +325,7 @@
   info = VEC_index (ssa_name_info_p, info_for_ssa_name, ver);
   if (info->age < current_info_for_ssa_name_age)
     {
-      info->need_phi_state = 0;
+      info->need_phi_state = NEED_PHI_STATE_UNKNOWN;
       info->current_def = NULL_TREE;
       info->age = current_info_for_ssa_name_age;
     }