When selecting a memory type, there are some property flags we need
(e.g., VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT, without which we cannot
vkMapMemory), and others we'd simply prefer (e.g.,
VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT, which may have a performance
impact, but otherwise shouldn't be required).
By specifying these separately, we can fall back to a memory type which
doesn't have everything we want, but which should still work, rather
than giving up.
Signed-off-by: David Gow <david@ingeniumdigital.com>
c172fb5972