Skyrim for Android 0.27.6

APK: Skyrim-0.27.6.apk (arm64-v8a, Android 9+, Vulkan 1.1).
SHA-1 ea75be239908f510bd6d9be0634ea146f4ce3b8d

This build fixes the stutter that 0.27.4 and 0.27.5 introduced on phones with several fast cores.

Fixed

Game threads stay on the fast cores when there are 4 or more of them. In 0.27.5, every thread except the main one was allowed onto the little cores. On chips with plenty of fast cores, Skyrim's job and Havok threads then landed on little cores, and the main thread waited on them every frame. Now:
- With 4 or more fast cores, the game's threads stay on the fast cores, as in 0.25.1. Only threads that Skyrim itself marks as below normal priority (streaming, IO and background work) can use every core.
Gentler back-off for spin-waiting workers. 0.27.5 made a worker sleep 50 µs after 32 back-to-back Sleep(0) calls. A worker now sleeps only after 256 back-to-back calls, and then for 20 µs.
Switching away from the game could crash it while DXVK recreated the screen surface with no window. DXVK now checks whether the game window still has its Android surface and waits for it to come back instead.
On some phones the screen surface is a different size from the window size that SDL reports, for example because of the camera cutout or the navigation-bar area. The picture was drawn at SDL's size into the larger surface, which left a black strip. The picture is now mapped onto the surface's real size.

Create an empty file port/save/noasync.txt in the game folder, and shaders compile during the frame instead of on a background thread. That gives constant rendering with the occasional hitch the first time each shader is seen, instead of objects popping in.

These go in port/save. Each one is an empty file.

File	Effect
`fastcores.txt`	Every game thread on the fast cores (as 0.25.1)
`allcores.txt`	Every thread on every core
`singlecore.txt`	Pin to one core
`noasync.txt`	Shaders compile in-frame (new)

Please attach port/log.txt from your Skyrim folder to any bug report.