Hojun-Cho
6a586cf792
wwstage-only. cglet had no 16B whole-tuple-from-call receive branch, so `let t = call()` whose callee returns a 2-eightbyte (16B) tuple fell through to the generic single-word store (MOVQ AX, off(BP)) and never spilled word1 (the DX eightbyte) — silent loss of t.1. Align to cstage cgen.c:6652, which spills both AX->off+0 and DX->off+8. Not a tupstore cursor off-by-one and not f64-specific: the destructure form `let (a,b) = call()` (cgmlet + tupstore cursor) was already byte-id; only the whole-tuple N_LET receive dropped word1, for any element mix incl. all-integer (i64,i64). An f64 element surfaced it first. The f64 element rides its eightbyte in AX/DX at receive and is re-read from X0/XMM at field-read (already byte-id), so no SSE cursor is needed.