thread.c: disable VM events when stack overflow
* thread.c (ruby_thread_stack_overflow): disable VM events when
stack overflow occurred; it causes another stack overflow again
in making backtrace object, and crashes.
[ruby-core:80662] [Bug #13425]
increase timeout seconds.
* test/ruby/test_trace.rb (test_trace_stackoverflow): on some platforms
this test fails because of timeout.
disable rewind hooks.
* vm.c (hook_before_rewind): skip rewind hooks if err is SystemStackError
because rewind hooks can cause stack overflow again and again.
* thread.c (ruby_thread_stack_overflow): do not disable all hooks.
Additionally, clearing ruby_vm_event_flags is not suitable way
to disable hooks.
merge revision(s) 58334,58346,58349: [Backport #13425] [Backport #13432]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@59297 b2dd03c8-39d4-4d8f-98ff-823fe69b080e