* process.c (rb_f_exec): Call before_exec_async_signal_safe and
  after_exec_async_signal_safe around rb_exec_async_signal_safe.
  (rb_exec_async_signal_safe): Don't call
  before_exec_async_signal_safe and after_exec_async_signal_safe.
  (rb_exec_without_timer_thread): Call before_exec and
  after_exec.
  (disable_child_handler_fork_child): Make SIGPIPE handler SIG_DFL.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47421 b2dd03c8-39d4-4d8f-98ff-823fe69b080e