merge revision(s) b8386f7f7f6d7a7d76481e02d389d0f5211f0f2c [Backport #18161]
Prepend DebugSystem to VCS class only And revert 24e5f1c982966c379220b1bbb26b4e0320180fa1, pepending to Kernel did not affect the top level methods before 3.0.
merge revision(s) b8386f7f7f6d7a7d76481e02d389d0f5211f0f2c [Backport #18161]