* include/ruby/signal.h: removed.
* common.mk, class.c, eval.c, eval_intern.h, file.c, gc.c, hash.c,
io.c, process.c, signal.c: vm_core.h: ditto.
Some unused external global variables are also removed.
(rb_prohibit_interrupt, rb_trap_immediate, rb_trap_pending,
rb_thread_critical)
* ext/openssl/ossl_ssl.c, ext/openssl/ossl_x509store.c,
ext/readline/readline.c, ext/socket/depend,
ext/socket/socket.c: ditto.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@19080 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
204929af9d