`VK_KHR_buffer_device_address` extends `VkMemoryAllocateFlagBits` but doesn't require it

In the spec for the `VK_KHR_buffer_device_address` extension, it says that it extends the `VkMemoryAllocateFlagBits` type with new values. But that type is only available from Vulkan 1.1 or with the `VK_KHR_device_group` extension, and the `VK_KHR_buffer_device_address` extension requires neither of these. This leads to a problem further down the line, because you are required to use the two added bit values for certain VUIDs, but you can't include them if `VkMemoryAllocateFlagBits` is not available.