* eval.c (rb_thread_start_0): fixed memory leak.
* parse.y (none): should clear cmdarg_stack too.
* io.c (rb_fopen): use setvbuf() to avoid recursive malloc() on
some platforms.
* file.c (rb_stat_dev): device functions should honor stat field
types (except long long such as dev_t).
* eval.c (rb_mod_nesting): should not push nil for nesting array.
* eval.c (rb_mod_s_constants): should not search array by
rb_mod_const_at() for nil (happens for singleton class).
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_6@1320 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
