SuperChunk - Extreme chunk generation

SuperChunk 0.6.1!

• fp32 GPU mode is about 30% faster: 1,468 → 1,915 chunks/s, level with the default mode. (14700k & 3070)
• With `gpu.desiredFp=fp32`, or on a GPU without double precision, the GPU now also decides each block (stone, air, water, lava, ore veins). Before, it handed that work back to the CPU.
• fp32 terrain was never identical to vanilla. The GPU block decisions add about 1 differing block in 3 million. The default (fp64) mode is unchanged.
• Distant Horizons: low-detail LODs are about 85% faster to compute, with the same heights.
• Distant Horizons: SuperChunk's data-stream speedup now applies. Forge's older Mixin skipped it with an "@Redirect conflict" warning. (Forge)

Fixes

• Intel integrated graphics: GPU generation never worked on Intel iGPUs (0.6.0 included). Every GPU batch failed with OpenCL error -5, and the CPU did all the work. It now runs on the iGPU, with about 20% less CPU per chunk. (UHD 770)
• Chunky stopping for good at the same percentage ("freezes at 62%"): when a chunk failed to generate, the chunks around it waited for it forever and Chunky ran out of slots. They now give up and Chunky carries on.
• TPS drops while Distant Horizons generates, even in superflat worlds: the server now holds 20 TPS.
• Collections Of Optimizations (#31): fixed the world-load crash ("cannot reduce visibility of PUBLIC target method"). SuperChunk no longer makes hidden vanilla methods public, which crashed any mod that replaces one of them.