getopt's deleted appendoption helper fed rt_ensure a hardcoded
membsz=24, stale since str went 24B (option {rune,str} = 32B): the
8-slot first grow allocated 192B while writes strode 32 — OOB past 6
options. The builtin derives 32 from the type table (MOVQ $32, SI);
this row appends 8 option literals and reads element 7 back full-width
so the class stays pinned. No in-tree test parsed >3 options.
Hojun-Cho
91d42d28ab