Add support for per-location warning groups.

gcc/lto/ChangeLog:

	* gimple-streamer-out.c (output_gimple_stmt): Same.
	* lto-common.c (compare_tree_sccs_1): Expand use of TREE_NO_WARNING.
	* lto-streamer-out.c (hash_tree): Same.
	* tree-streamer-in.c (unpack_ts_base_value_fields): Same.
	* tree-streamer-out.c (pack_ts_base_value_fields): Same.

diff --git a/gcc/gimple-streamer-out.c b/gcc/gimple-streamer-out.c
index fcbf92300d4..7f7e06a79b8 100644
--- a/gcc/gimple-streamer-out.c
+++ b/gcc/gimple-streamer-out.c
@@ -73,7 +73,7 @@ output_gimple_stmt (struct output_block *ob, struct function *fn, gimple *stmt)
   /* Emit the tuple header.  */
   bp = bitpack_create (ob->main_stream);
   bp_pack_var_len_unsigned (&bp, gimple_num_ops (stmt));
-  bp_pack_value (&bp, gimple_no_warning_p (stmt), 1);
+  bp_pack_value (&bp, warning_suppressed_p (stmt), 1);
   if (is_gimple_assign (stmt))
     bp_pack_value (&bp,
 		   gimple_assign_nontemporal_move_p (
diff --git a/gcc/lto-streamer-out.c b/gcc/lto-streamer-out.c
index a26d4885800..f1809e60c1e 100644
--- a/gcc/lto-streamer-out.c
+++ b/gcc/lto-streamer-out.c
@@ -1207,7 +1207,7 @@ hash_tree (struct streamer_tree_cache_d *cache, hash_map<tree, hashval_t> *map,
   if (TYPE_P (t))
     hstate.add_flag (TYPE_ARTIFICIAL (t));
   else
-    hstate.add_flag (TREE_NO_WARNING (t));
+    hstate.add_flag (warning_suppressed_p (t));
   hstate.add_flag (TREE_NOTHROW (t));
   hstate.add_flag (TREE_STATIC (t));
   hstate.add_flag (TREE_PROTECTED (t));
diff --git a/gcc/lto/lto-common.c b/gcc/lto/lto-common.c
index bfe52a2e942..9e7ea877e66 100644
--- a/gcc/lto/lto-common.c
+++ b/gcc/lto/lto-common.c
@@ -1110,8 +1110,8 @@ compare_tree_sccs_1 (tree t1, tree t2, tree **map)
     compare_values (TYPE_UNSIGNED);
   if (TYPE_P (t1))
     compare_values (TYPE_ARTIFICIAL);
-  else
-    compare_values (TREE_NO_WARNING);
+  else if (t1->base.nowarning_flag != t2->base.nowarning_flag)
+    return false;
   compare_values (TREE_NOTHROW);
   compare_values (TREE_STATIC);
   if (code != TREE_BINFO)
diff --git a/gcc/tree-streamer-in.c b/gcc/tree-streamer-in.c
index e0522bf2ac1..31dbf2fb992 100644
--- a/gcc/tree-streamer-in.c
+++ b/gcc/tree-streamer-in.c
@@ -131,7 +131,8 @@ unpack_ts_base_value_fields (struct bitpack_d *bp, tree expr)
   if (TYPE_P (expr))
     TYPE_ARTIFICIAL (expr) = (unsigned) bp_unpack_value (bp, 1);
   else
-    TREE_NO_WARNING (expr) = (unsigned) bp_unpack_value (bp, 1);
+    /* FIXME: set all warning bits. */
+    suppress_warning (expr, N_OPTS, (unsigned) bp_unpack_value (bp, 1));
   TREE_NOTHROW (expr) = (unsigned) bp_unpack_value (bp, 1);
   TREE_STATIC (expr) = (unsigned) bp_unpack_value (bp, 1);
   if (TREE_CODE (expr) != TREE_BINFO)
diff --git a/gcc/tree-streamer-out.c b/gcc/tree-streamer-out.c
index 855d1cd59b9..b76e0c59c6f 100644
--- a/gcc/tree-streamer-out.c
+++ b/gcc/tree-streamer-out.c
@@ -104,7 +104,8 @@ pack_ts_base_value_fields (struct bitpack_d *bp, tree expr)
   if (TYPE_P (expr))
     bp_pack_value (bp, TYPE_ARTIFICIAL (expr), 1);
   else
-    bp_pack_value (bp, TREE_NO_WARNING (expr), 1);
+    /* FIXME: pack all warning bits.  */
+    bp_pack_value (bp, warning_suppressed_p (expr), 1);
   bp_pack_value (bp, TREE_NOTHROW (expr), 1);
   bp_pack_value (bp, TREE_STATIC (expr), 1);
   if (TREE_CODE (expr) != TREE_BINFO)