--- every @class/@stuck/@crack note in this translation unit ---
// @class: iv-combine
// @stuck: none — MATCH (49 ins). gcc folds (v0+0x1800)-0x1000 -> v0+0x800; re-tie barrier on the WORKING reg v0 (NOT a saved local) forces the target chain v0=base+0x1800; s2=copy; v0-=0x1000; s1=v0<<5. NO register pins (pins re-trigger the lhu/lh dual-load CSE collapse and shrink the frame; natural alloc gives s0-s3 + frame 0x38).
// @class: regalloc-order
// @stuck: none — MATCH
// @class: regalloc-order
// @stuck: none — MATCH (param_1 naturally lands in $s0 across the call, mirrors sibling func_80184AEC)
// @class: plumbing
// @stuck: none — MATCH (expected)
