Do not zero-init stack in vprintf
Do not zero-init stack in vprintf

8cc produces long code to zero-fill it.

ND-CSE-30151/elvm,ND-CSE-30151/elvm,shinh/elvm,shinh/elvm,shinh/elvm,shinh/elvm,shinh/elvm,shinh/elvm,shinh/elvm,ND-CSE-30151/elvm,shinh/elvm