* lang.c (flag_hash_synchronization): New global.
(lang_f_options): Added `hash-synchronization'.
* lang-options.h: Mention -fhash-synchronization.
* java-tree.h (flag_hash_synchronization): Declare.
* expr.c (java_lang_expand_expr): Only push `sync_info' value when
hash table synchronization is disabled.
* decl.c (init_decl_processing): Only push `sync_info' value when
hash table synchronization is disabled.
* class.c (make_class_data): Only push `sync_info' field when hash
table synchronization is disabled. Removed dead code.