test: mark test-vm-syntax-error-stderr as flaky
test: mark test-vm-syntax-error-stderr as flaky

Ref: https://github.com/nodejs/node/issues/2660

PR-URL: https://github.com/nodejs/node/pull/2662
Reviewed-By: orangemocha - Alexis Campailla <9c2cdb724be23f67dce68366531dd149b4c97628@nodejs.org>

dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node