Function vkCreateValidationCacheEXT 

pub unsafe extern "system" fn vkCreateValidationCacheEXT(
    device: VkDevice,
    pCreateInfo: *const VkValidationCacheCreateInfoEXT,
    pAllocator: *const VkAllocationCallbacks,
    pValidationCache: *mut VkValidationCacheEXT,
) -> VkResult

Available if built with prototypes.