Guest shaders that reserve a compacted output slot via subgroup ballot
-> popcount -> atomic add cannot preserve the originating primitives'
relative order once run through the single-invocation subgroup
fallback for stages without subgroup support. gl_PrimitiveId is
already hardware-guaranteed unique and monotonically increasing per
primitive, so CompactionFallbackPass rewrites that pattern into a
gl_PrimitiveId-indexed scatter instead.
Confirmed fixing corrupted/order-scrambled compacted draws in NieR
Automata on a device without geometry-stage subgroup support.
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4330
CamilleLaVey
Aydar Kamaltdinov