The lone js opt-in-JIT residual was async/await_in_loop, which failed to PARSE
under JIT ("Unexpected token: op '<'" on `i < 5`) while passing on CEK. The js
exclusion was "js-*", but the recursive-descent parser is the jp-* namespace
(75 functions in lib/js/parser.sx) — only the lexer/transpile/runtime are js-*.
So the parser was left JIT-eligible and a jp-* function miscompiled this
construct (the long-standing parser-miscompile class).
Fix: extend the js exclusion to "js-* jp-*" so the parser is interpret-only too,
matching how every other guest's front-end is handled. js conformance under
SX_SERVING_JIT=1 is now 148/148, == CEK.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
giles
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