vm.c: suppress warnings
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40760 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
vm.c: suppress warnings
volatile to suppress -Wclobbered warnings by gcc 4.9.0.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40760 b2dd03c8-39d4-4d8f-98ff-823fe69b080e