Free constructor elts in LTO merging

[Jan Hubicka]

Hi,
according to memory stats this is relatively common reason for garbage left
after tree merging.

Bootstrapped/regtested x86_64-linux, OK?

Honza

        * lto/lto.c (unify_scc): Free also CONSTRUCTOR_ELTS.
Index: lto/lto.c
===================================================================
--- lto/lto.c   (revision 207515)
+++ lto/lto.c   (working copy)
@@ -1807,8 +1807,13 @@ unify_scc (struct streamer_tree_cache_d
          /* Free the tree nodes from the read SCC.  */
          for (unsigned i = 0; i < len; ++i)
            {
+             enum tree_code code;
              if (TYPE_P (scc->entries[i]))
                num_merged_types++;
+             code = TREE_CODE (scc->entries[i]);
+             if (CODE_CONTAINS_STRUCT (code, TS_CONSTRUCTOR)
+                 && CONSTRUCTOR_ELTS (scc->entries[i]))
+               ggc_free (CONSTRUCTOR_ELTS (scc->entries[i]));
              ggc_free (scc->entries[i]);
            }