thread.c: disable VM events when stack overflow
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58334 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
thread.c: disable VM events when stack overflow
stack overflow occurred; it causes another stack overflow again
in making backtrace object, and crashes.
[ruby-core:80662] [Bug #13425]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58334 b2dd03c8-39d4-4d8f-98ff-823fe69b080e