[jdalton]

Summary

Follow-up to #8341. sdxgen's ReferenceError: node_process is not defined is eliminated. The HIR was dropping the built-in require binding before the wrap's runtime createRequire path could run.

Root cause (mechanism (a))

#8341 made the CJS wrap route built-in requires (require("process")) through the synthetic require's createRequire arm instead of the hoisted static import binding, and skipped alias adoption/blanking for built-ins. That logic is correct, but the binding was being dropped before the wrap's runtime path could use it.

The HIR's destructuring var/let/const pass (register_native_fetch_and_streams / register_destructured_stream_ctors) rewrites let node_process = require("process") into a native-module namespace binding (register_require_namespace_binding → remove_local_binding), mirroring import * as node_process from "process". This pass runs before call lowering, so the lookup_local("require") guard in try_require_literal (which would otherwise bail because the wrap's synthetic function require shadows the global) never fires. The codegen does not initialize native-module import bindings inside CJS-wrapped modules, so node_process resolved to nothing at runtime — the ReferenceError.

So the mechanism is (a): the HIR drops the built-in require binding via the destructuring native-require fast path, which is out of sync with the wrap fix — it matches the bare require ident even when shadowed by the wrap's synthetic function require, unlike try_require_literal which checks lookup_local("require"). This is NOT (b) (the synthetic require's createRequire fallback is reached and works) and NOT (c) (no separate blanking path — #8341's blanking skip is effective).

Fix (three parts)

1. HIR (var_decl_sources.rs / native_fetch.rs): gate the destructuring native-require fast paths on require being the bare global (not shadowed by the wrap's synthetic function require), via a new require_is_shadowed_by_local helper that mirrors try_require_literal's guard. When shadowed, the require("<builtin>") call flows through to the synthetic require, which resolves builtins via createRequire.

2. wrap (wrap.rs): stop emitting import _req_N from '<builtin>' for built-in specs — the binding is never initialized in a CJS-wrapped module and is now unreferenced.

3. wrap (wrap.rs): the per-spec require case for builtins never references the (now nonexistent) import local — always go through the createRequire-backed required_value, including the try-site branch (the typeof {local} === 'boolean' sentinel guard does not apply to builtins).

Verification

• ReferenceError: node_process is not defined is gone — confirmed by running the compiled sdxgen.
• Minimal CJS witnesses compile, link, and print darwin:
  • const p = require("process"); console.log(p.platform) (and os/path)
  • the exact rolldown __toESM shape (let node_process = require("process"); node_process = __toESM(node_process, 1), with the real Object.create(Object.getPrototypeOf(mod)) helper)
  • the destructured const { platform } = require("process")
• New regression tests: wrap-level (cjs_wrap_builtin_require_not_hoisted_as_static_import) and end-to-end (cjs_wrap_builtin_require.rs — 3 tests, all green).
• cargo test for touched crates green, measured: perry-hir lib 315 passed; perry cjs_wrap unit 112 passed; createrequire_builtin_modules integration 5 passed (no regression in the createRequire path).

Separate newly-revealed blocker (not this PR's scope)

With the ReferenceError fixed, sdxgen now reveals a separate downstream runtime error: TypeError: Object prototype may only be an Object or null: -2 at external-pack.js (from __toESM's Object.create(Object.getPrototypeOf(mod)), where Object.getPrototypeOf returns -2 for some reified CJS chunk exports object). This is a different Perry runtime bug (Object prototype reification / getPrototypeOf returning a tagged sentinel for a specific reified object), not the CJS-wrap/HIR-drop mechanism this PR fixes. It was masked by the ReferenceError and needs its own follow-up. The assigned blocker (ReferenceError: node_process is not defined) is resolved.