Add the primitive wrapper unit and its gated runtime feature

scr_js_wrapper.c constructs `new String/Number/Boolean` wrappers and
ToObject of a primitive as ordinary dictionary-mode objects whose
prototype is the unit's String, Number or Boolean prototype, with the
[[PrimitiveValue]] slot on the object's source identity. The unit also
answers instanceof, Object.prototype.toString, the util.types brands,
the String method receiver, and the guard of the graph-walking consumers
that cannot read the slot yet. A new `primitiveWrapper` runtime feature
(any `wrapper.` libCall) links it, so a program that never creates a
wrapper links no byte of the unit and the zero-cost gate keeps fully
typed programs clean. The `wrapper.*` signatures, symbols and dispatch
case are registered here; no frontend emits them yet.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/compiler/src/executable/executable-cache.ts

@@ -68,6 +68,7 @@ export interface EarlyExecutableNativeFeatures {
   nodeIsland?: boolean;
   moduleNamespace?: boolean;
   moduleNamespaceDyn?: boolean;
+  primitiveWrapper?: boolean;
   zlib: boolean;
   brotli?: boolean;
   assert: boolean;