Merged requested to merge pixelcluster/mesa:radv_ue4_timestamp_sync into main
UE4's Vulkan backend uses vkCmdWriteTimestamp with TOP_OF_PIPE to measure how long a workload took in the GPU Benchmark. This is wrong and writes the timestamp before the workload is actually finished, making it seem like the GPU is much faster than it actually is. This caused subsequent benchmark passes to contain way too big workloads, which caused soft hangs on slower GPUs.
Fixes GPU hangs with Splitgate during automatic settings configuration.