Zero bootstrap patches: all 11 moved to spec or runtime

- make-raise-guard-frame: was never defined in spec — added it
- *last-error-kont*: set at error origination (host-error calls), not
  wrapped around every cek-run step. Zero overhead on normal path.
- JIT: jit-try-call runtime function called from spec. Platform
  registers hook via _jit_try_call_fn ref. No bootstrap patching.
- bootstrap.py compile_spec_to_ml() now returns transpiled output
  with zero post-processing.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

hosts/ocaml/transpiler.sx

@@ -252,7 +252,8 @@
     "component-set-file!"
     "parse-comp-params"
     "parse-macro-params"
-    "parse-keyword-args"))
+    "parse-keyword-args"
+    "jit-try-call"))
 
 (define
   ml-is-known-name?