zluda: coalesce pair shadow stores, signed native FP8 conversion

Patch 0011 merges a complete accumulator-register pair overwrite into one
shadow-layout conversion (reads, rewritten shadow accesses and block
boundaries prevent it; partial writes keep read/modify/write), and requests
eight waves per SIMD for gfx12 native-FP8 functions. Patch 0012 keeps signs
in the native conversion: finite overflow clamped, NaNs mapped to signed
infinity, post-conversion sign masks gone; plain and ReLU remain
exhaustive-table identical to the software codec.

Eighty-frame harness at 720p->4K, excluding the first twenty: control
24.764 ms, coalescing 23.340 ms, plus eight waves 20.135 ms, plus signed
conversion 16.234 ms (15.144 ms with the harness idle gap removed); all
eighty saved frames byte-identical to the matching control. Twelve- and
ten-wave budgets regress (25.56/24.61 ms); fast math changes the image
(18.92 ms) and is not selected.

packaging/SOURCES.txt

@@ -13,7 +13,7 @@ Built from source by d4r (GPL-3.0-only, d4r/licenses/d4r-LICENSE.txt):
 
 Third-party software, unmodified or patched by d4r:
   d4r/zluda/libcuda.so   ZLUDA (Apache License 2.0 or MIT), https://github.com/vosen/ZLUDA
-                         commit @ZLUDA_COMMIT@ with d4r/source/patches/zluda/0002 to 0008 applied.
+                         commit @ZLUDA_COMMIT@ with d4r/source/patches/zluda/0002 to 0012 applied.
                          It contains LLVM (Apache License 2.0 with LLVM exceptions).
                          Licenses: d4r/licenses/ZLUDA-LICENSE-*.txt, d4r/licenses/LLVM-LICENSE.txt
   d3d12.dll, d3d12core.dll