retina_on was being set (indirectly) by check_retina_status(), but it
relies on retina_on itself.
This resulted in incorrect (non-retina) monitor and work RECTs being
cached, causing odd application bugs like a window that won't resize
larger than 1/4 of the screen.

Initialize retina_on to the value of retina_enabled, so later calls
to check_retina_status() don't result in incorrect data being cached.

Introduced in 98d20975.
An application (Idol Showdown) fails to play its intro video without
this change.
Signed-off-by: Eric Pouech <epouech@codeweavers.com>

And use the correct 32-bit types for the conversion.

Based on the similar tests for NtAllocateVirtualMemoryEx().

Based on vkd3d commit d8ef0c69a817d059b1d4fc62520131eed80aba29.

Based on vkd3d commit ee52ad810635cf504a49d5267a5942fffb16836e.

Rely on the swapchain to reference its individual textures, and rely on the
parent texture object to keep the swapchain alive if necessary.

This is necessary to allow detaching textures from a swapchain.