* vm_trace.c, vm.c, thread.c: get rid of (maybe false positive) warnings about
  using uninitialized var with VC++.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46237 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2014-05-30

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46238 b2dd03c8-39d4-4d8f-98ff-823fe69b080e