Uninitialized boxes: check for zero-size allocation based on Layout::size
Uninitialized boxes: check for zero-size allocation based on Layout::size

aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,graydon/rust