Perf round 1: self-call, keyword interning, fast record field reads (#221)

simon/jolt

* Make the benchmark harness build optimized binaries on Chez

bench/run.sh was Janet-era: it invoked a 'jolt' binary and set
JOLT_DIRECT_LINK/JOLT_WHOLE_PROGRAM, none of which exist on Chez, where
'joltc run -m' runs fully unoptimized (direct-link and inline default off). So
the suite was measuring jolt's unoptimized path.

run.sh now compiles each benchmark to an optimized AOT binary (joltc build
--direct-link --opt) and times it against JVM Clojure on the same portable
source, auto-detecting the Chez kernel dev files like build-smoke.sh. Adds
bench/deps.edn so joltc resolves the namespaces, NO_JVM to skip the reference.

mandelbrot.clj dropped its jolt.png require so the JVM reference can run it; the
picture demo moved to mandelbrot_png.clj (jolt-only). README scorecard refreshed
with current Chez numbers and the two-regime read (compute ~8-10x substrate floor;
dispatch/alloc ~120-330x architectural gaps the passes don't touch). Stale
'jolt -m' header lines point at bench/run.sh.

* Emit direct self-calls for named-fn self-recursion

A self-recursive call to a named fn compiled to (jolt-invoke fib ...) instead of
a direct (fib ...): emit-invoke handled a :local callee only when it was NOT a
known proc, so a :local that IS in *known-procs* (the letrec-bound self-name) fell
through to the :else jolt-invoke branch. Now a :local known proc emits a direct
Scheme call — no jolt-invoke, no per-call arg-list consing; case-lambda handles
arity.

fib 30: 63.3ms -> 4.7ms (faster than JVM Clojure's 7.1ms; was 9x slower). The win
is on every self-recursive non-loop fn, including the compiler's own. No semantic
change — selfhost holds, make test green, shakesmoke/buildsmoke byte-identical.

Re-mint (backend is seed). Corpus rows pin self-recursion across fixed/multi/
variadic arities.

* Intern no-ns keywords without per-call allocation

(keyword #f name) built a fresh combined-key string (string-append) on every
call just to do the intern-table lookup — ~80 bytes of garbage per (:kw x), map
literal, keyword arg, etc. A no-ns keyword now interns in a table keyed by the
name string directly, so a lookup of an already-interned keyword is one
hashtable-ref with no allocation. The ns table keeps the combined key; both share
the keyword-t khash (equal-hash of the combined key) so hash values are unchanged.

Small time win on its own (the field-read dispatch dominates hot record code —
see jolt-unx4) but removes per-call keyword allocation everywhere. Runtime .ss,
no re-mint; identity/=/hash unchanged, make test green.

* Fast record field reads: single eq? scan, skip the get-arm walk

(:field rec) / (get rec :field) lowers to (jolt-get rec kw), which walked the
get-arm list to reach the jrec arm, then did jrec-has? + jrec-lookup — TWO linear
scans, each comparing keys through the generic jolt=2 equality dispatcher. Field
keys are interned keywords, so:

- jrec-key=? compares a keyword query by eq? (jolt=2 only for non-keyword keys),
- jrec-ref does ONE scan (vs has?+lookup) and runs a deftype's ILookup valAt only
  when the field is genuinely absent (present-nil still returns nil, not default),
- jolt-get-dispatch checks jrec? first, skipping the get-arm walk for the hottest
  get target. jrec-lookup/jrec-has? (used by =, contains?, etc.) get the fast
  compare too.

binary-trees 135x->18.9x, dispatch 121x->26.4x, mono-dispatch 327x->108x vs JVM.
Runtime .ss (collections.ss + records.ss), no re-mint; make test + shakesmoke +
buildsmoke green, record get/assoc/keys/=/count semantics unchanged.

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Co-authored-by: Yogthos <yogthos@gmail.com>

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