* process.c (pst_wstopsig): returns nil unless WIFSTOPPED() is
non-zero.
* process.c (pst_wtermsig): returns nil unless WIFSIGNALED() is
non-zero.
* process.c (pst_wexitstatus): returns nil unless WIFEXITED() is
non-zero.
* eval.c (rb_thread_select): tv_sec and tv_usec should not be
negative.
* signal.c (posix_signal): do not set SA_RESTART for SIGVTALRM.
* parse.y (call_args2): block_arg may follow the first argument in
call_args2.
* eval.c (stack_check): should avoid stack length check during
raising SystemStackError exception.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@1852 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
f1fdbf080e