This is required by the Metal backend to perform flushing of temporary objective-C resources. This is implemented as a global autoreleasepool, and is to ensure consistency such that all rendering operations, whether called via events, or via main loop will be within an autoreleasepool.
Authored by Apple: Michael Parkin-White
Ref T96261
Reviewed By: fclem
Differential Revision: https://developer.blender.org/D15900
Leading to excessive memory usage compared to Blender 2.93. There's still
some avoidable memory usage remaining, due to the full float buffer in the
new image editor drawing and not loading the cached EXR from disk in tiles.
Main difficulty was handling multi-image baking and disk caches, which is
solved by associating a unique layer name with each image so it can be
matched when reading back the image from the disk.
Also some minor header changes to be able to use RE_MAXNAME in RE_bake.h.