nx_qsort.nx

nx_qsort.nx -- in-place quicksort for i64 arrays + a generic indirect variant that takes a comparator function pointer. Used by: - nx_link / nx_objdump / nx_nm: sort symbols by address or name. - nx_dwarf_line: sort PC ranges before emitting the line program. - nx_audit / nx_metrics: sort scores for top-N reporting. Today most NishiLang call sites do bubble-sort or insertion-sort inline, which is fine for tiny arrays but quadratic above ~50 elements. This module gives O(n log n) average + O(log n) stack. Implementation notes: - Lomuto partition (simpler than Hoare; the constant-factor difference doesn't matter when symbol counts are < 100k). - Recursion bound = log2(n) + small constant; for n = 1M, that is ~20 frames -- fits even a tiny call stack. - When n <= 16 we fall back to insertion sort (lower overhead for small arrays; classic optimisation).