kernel+bundle: fix nil-bytecode .sxbc (compile-blob serializer dropped Integer)

Every .sxbc shipped with `:bytecode (nil nil ...)` and `:arity nil`, so the WASM
kernel's vm.sx hit "VM: unknown opcode 0" on every module and fell back to .sx
source (slower, noisy console). Root cause: `raw_serialize` in the `compile-blob`
command (sx_server.ml) handles `Number` but not `Integer`, and bytecode opcodes +
arity/upvalue-count are `Integer`s — so they fell through to the `_ -> "nil"`
catch-all and serialized as nil. Same class of bug as the value_to_js Integer gap
(689dae7d). It went unnoticed because source-fallback masks it. Add the Integer
case and regenerate: the web stack now loads entirely from bytecode (0 unknown-
opcode warnings, 0 source fallbacks), boost + SPA unchanged. compiler.sx in the
bundle was also stale — re-synced to the canonical lib/compiler.sx.

Verified: native host conformance 271/271; chromium boots with 0 unknown-opcode
warnings + 0 source-fallback loads; spa-check still passes (boost 6/6, fragment
swap). Prereq for content-addressing the assets (caching real bytecode, not nil).

shared/static/wasm/sx/compiler.sx

@@ -783,11 +783,7 @@
                 (rest-clauses
                   (if (> (len flat-args) 2) (slice flat-args 2) (list))))
               (if
-                (or
-                  (and
-                    (= (type-of test) "keyword")
-                    (= (keyword-name test) "else"))
-                  (= test true))
+                (or (and (= (type-of test) "keyword") (= (keyword-name test) "else")) (and (= (type-of test) "symbol") (or (= (symbol-name test) "else") (= (symbol-name test) ":else"))) (= test true))
                 (compile-expr em body scope tail?)
                 (do
                   (compile-expr em test scope false)
@@ -828,11 +824,7 @@
               (rest-clauses
                 (if (> (len clauses) 2) (slice clauses 2) (list))))
             (if
-              (or
-                (and
-                  (= (type-of test) "keyword")
-                  (= (keyword-name test) "else"))
-                (= test true))
+              (or (and (= (type-of test) "keyword") (= (keyword-name test) "else")) (and (= (type-of test) "symbol") (or (= (symbol-name test) "else") (= (symbol-name test) ":else"))) (= test true))
               (do (emit-op em 5) (compile-expr em body scope tail?))
               (do
                 (emit-op em 6)
@@ -1008,11 +1000,27 @@
             (let
               ((name (symbol-name head))
                 (argc (len args))
-                (name-idx (pool-add (get em "pool") name)))
+                (specialized-op (cond
+                  (and (= argc 2) (= name "+")) 160
+                  (and (= argc 2) (= name "-")) 161
+                  (and (= argc 2) (= name "*")) 162
+                  (and (= argc 2) (= name "/")) 163
+                  (and (= argc 2) (= name "=")) 164
+                  (and (= argc 2) (= name "<")) 165
+                  (and (= argc 2) (= name ">")) 166
+                  (and (= argc 2) (= name "cons")) 172
+                  (and (= argc 1) (= name "not")) 167
+                  (and (= argc 1) (= name "len")) 168
+                  (and (= argc 1) (= name "first")) 169
+                  (and (= argc 1) (= name "rest")) 170
+                  :else nil)))
               (for-each (fn (a) (compile-expr em a scope false)) args)
-              (emit-op em 52)
-              (emit-u16 em name-idx)
-              (emit-byte em argc))
+              (if specialized-op
+                (emit-op em specialized-op)
+                (let ((name-idx (pool-add (get em "pool") name)))
+                  (emit-op em 52)
+                  (emit-u16 em name-idx)
+                  (emit-byte em argc))))
             (do
               (compile-expr em head scope false)
               (for-each (fn (a) (compile-expr em a scope false)) args)
@@ -1156,11 +1164,7 @@
               (test (first clause))
               (body (rest clause)))
             (if
-              (or
-                (and
-                  (= (type-of test) "keyword")
-                  (= (keyword-name test) "else"))
-                (= test true))
+              (or (and (= (type-of test) "keyword") (= (keyword-name test) "else")) (and (= (type-of test) "symbol") (or (= (symbol-name test) "else") (= (symbol-name test) ":else"))) (= test true))
               (compile-begin em body scope tail?)
               (do
                 (compile-expr em test scope false)