cce35658a5
Port the D/DS-form update loads (lwzu, lhzu, lhau, lbzu, ldu) and stores (stwu, sthu, stbu, stdu) — ~10% of the boot fallback executions (stwu 6.1% + lwzu 2.4% + ldu/stdu 1.4% + ...). EA = gpr[rA] + EXTS(disp) with rA read directly (update forms are invalid for rA==0, and interp reads gpr[rA] with no 0-substitution); rD/mem then gpr[rA]=ea truncated to u32 and zero-extended (matches interp `... as u32; gpr[ra]=ea as u64`). Stores capture rS into rdx BEFORE the rA writeback so `stXu rS,d(rA)` with rS==rA stores the OLD rA value (interp order). New emit helpers emit_update_ea_writeback / emit_load_update / emit_load64_update / emit_store_update; all cache-aware (gld64/gst64 accessors). New differential test update_loadstore_matches (regcache forced on), incl. the store rS==rA case. 18 tests green. Fallback executions 25.55M -> 22.97M (-10.1%, n=200M). Golden n200m BYTE-IDENTICAL under interp, XENIA_JIT=1, and +XENIA_JIT_REGCACHE=1. Whole-run ratio 1.079x -> 1.077x: as prior evidence predicted, opcode coverage does not flip the JIT on this FP-video-decode-bound boot bench (62% of remaining fallbacks are fmadds/fmuls/fadds/fsubs, expensive in both paths). Correctness/coverage win; real speed lever is dispatch elimination (block-linking), not more opcodes. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>