Blender Git Loki

Fix T91639: Cycles crash rendering high resolution images with multiple passes

We were writing large 2048x2048 tiles into EXR files, which appears to cause
integer overflow inside the OpenEXR library when there are multiple passes. Now
use smaller tiles in the image file, while still rendering large tiles.

This adds the requirement that the render tile size must be a multiple of 128
or be smaller than 128, this is adjusted automatically.