Do not stream DECL_FCONTEXT

[Jan Hubicka]

Hi,
this is another field that I believe needs no streaming.  I however think we 
are pretty
much done with low hanging fruit.

lto-bootstrapped/regtested x86_64-linux, OK?

Honza

        * lto-streamer-out.c (DFS::DFS_write_tree_body): Do not stream
        DECL_FCONTEXT
        (hash_tree): Do not hash DECL_FCONTEXT
        * tree-streamer-in.c (lto_input_ts_field_decl_tree_pointers):
        Do not stream DECL_FCONTEXT.
        * tree-streamer-out.c (write_ts_field_decl_tree_pointers): Likewise.
        * tree.c (free_lang_data_in_decl): Free DECL_FCONTEXT.

Index: lto-streamer-out.c
===================================================================
--- lto-streamer-out.c  (revision 262560)
+++ lto-streamer-out.c  (working copy)
@@ -832,7 +832,7 @@ DFS::DFS_write_tree_body (struct output_
       DFS_follow_tree_edge (DECL_BIT_FIELD_TYPE (expr));
       DFS_follow_tree_edge (DECL_BIT_FIELD_REPRESENTATIVE (expr));
       DFS_follow_tree_edge (DECL_FIELD_BIT_OFFSET (expr));
-      DFS_follow_tree_edge (DECL_FCONTEXT (expr));
+      gcc_checking_assert (!DECL_FCONTEXT (expr));
     }
 
   if (CODE_CONTAINS_STRUCT (code, TS_FUNCTION_DECL))
@@ -1249,7 +1249,6 @@ hash_tree (struct streamer_tree_cache_d
       visit (DECL_BIT_FIELD_TYPE (t));
       visit (DECL_BIT_FIELD_REPRESENTATIVE (t));
       visit (DECL_FIELD_BIT_OFFSET (t));
-      visit (DECL_FCONTEXT (t));
     }
 
   if (CODE_CONTAINS_STRUCT (code, TS_FUNCTION_DECL))
Index: tree-streamer-in.c
===================================================================
--- tree-streamer-in.c  (revision 262560)
+++ tree-streamer-in.c  (working copy)
@@ -758,7 +758,6 @@ lto_input_ts_field_decl_tree_pointers (s
   DECL_BIT_FIELD_TYPE (expr) = stream_read_tree (ib, data_in);
   DECL_BIT_FIELD_REPRESENTATIVE (expr) = stream_read_tree (ib, data_in);
   DECL_FIELD_BIT_OFFSET (expr) = stream_read_tree (ib, data_in);
-  DECL_FCONTEXT (expr) = stream_read_tree (ib, data_in);
 }
 
 
Index: tree-streamer-out.c
===================================================================
--- tree-streamer-out.c (revision 262560)
+++ tree-streamer-out.c (working copy)
@@ -646,7 +646,6 @@ write_ts_field_decl_tree_pointers (struc
   stream_write_tree (ob, DECL_BIT_FIELD_TYPE (expr), ref_p);
   stream_write_tree (ob, DECL_BIT_FIELD_REPRESENTATIVE (expr), ref_p);
   stream_write_tree (ob, DECL_FIELD_BIT_OFFSET (expr), ref_p);
-  stream_write_tree (ob, DECL_FCONTEXT (expr), ref_p);
 }
 
 
Index: tree.c
===================================================================
--- tree.c      (revision 262560)
+++ tree.c      (working copy)
@@ -5280,6 +5280,7 @@ free_lang_data_in_decl (tree decl)
   free_lang_data_in_one_sizepos (&DECL_SIZE_UNIT (decl));
   if (TREE_CODE (decl) == FIELD_DECL)
     {
+      DECL_FCONTEXT (decl) = NULL;
       free_lang_data_in_one_sizepos (&DECL_FIELD_OFFSET (decl));
       if (TREE_CODE (DECL_CONTEXT (decl)) == QUAL_UNION_TYPE)
        DECL_QUALIFIER (decl) = NULL_TREE;