* tree-streamer.h (streamer_tree_cache_create): Adjust prototype.
* tree-streamer.c (streamer_tree_cache_create): Make maintaining
the map from cache entry to cache index optional.
(streamer_tree_cache_replace_tree): Adjust accordingly.
(streamer_tree_cache_append): Likewise.
(streamer_tree_cache_delete): Likewise.
* lto-streamer-in.c (lto_data_in_create): Do not maintain the
streamer cache map from cache entry to cache index.
* lto-streamer-out.c (create_output_block): Adjust.
lto/
* lto.c (lto_register_var_decl_in_symtab): Pass in cache index
and use it.
(lto_register_function_decl_in_symtab): Likewise.
(cmp_tree): New function.
(unify_scc): Instead of using the streamer cache map from entry
to cache index match up the two maps we have by sorting them.
Adjust calls to lto_register_var_decl_in_symtab and
lto_register_function_decl_in_symtab.