Function mi_zalloc_small 

pub unsafe extern "C" fn mi_zalloc_small(size: usize) -> *mut c_void

Allocate an zero-initialized object of no more than MI_SMALL_SIZE_MAX bytes.

Does not check that size is indeed small.

Note: Currently mi_zalloc checks if size is small and calls this if so at runtime, so its’ only worth using if you know for certain.