experimental.swcEnvOptions is not applied to server-side (Node) SWC compilation

Link to the code that reproduces this issue

https://github.com/izemo/izemo-next-app

To Reproduce

1. Clone the reproduction repo and pnpm install.
2. The repo is configured with:
   • next: 16.3.0-canary.5
   • engines.node: "22.22.2"
   • .browserslistrc: chrome 110
   • next.config.ts: experimental.swcEnvOptions: { mode: "usage", coreJs: "3.49" }
3. app/server/page.tsx is a Server Component (with export const dynamic = "force-dynamic") that calls RegExp.escape("a.b.c"). RegExp.escape is TC39 Stage 4 (ES2025) and is missing in both Chrome 110 and Node 22.22.2; it landed in Chrome 136 / Node 24.
4. app/client/page.tsx is the client-side mirror (call inside useEffect).
5. Run pnpm build --webpack and pnpm start.
6. curl -i http://localhost:3000/server.

Current vs. Expected behavior

Expected: With experimental.swcEnvOptions: { mode: "usage", coreJs: "3.49" },
SWC's preset-env should auto-inject the core-js polyfill for RegExp.escape
into BOTH the client bundle and the Node-side server bundle, since neither
browserslist target (chrome 110) nor engines.node (22.22.2) ships it natively.

Actual: The polyfill is injected only into the client bundle; the
server bundle emits the call as-is.

Evidence after pnpm build --webpack:

Client bundle (.next/static/chunks/app/client/page-*.js):
- escape:function polyfill body → 1 occurrence (core-js inlined) ✅

Server bundle (.next/server/app/server/page.js):
- escape:function polyfill body → 0 occurrences ❌
- Verbatim user code in bundle : RegExp.escape("a.b.c")

Hitting the route on Node 22.22.2 fails:

$ curl -i http://localhost:3000/server
HTTP/1.1 500 Internal Server Error
...
⨯ TypeError: RegExp.escape is not a function
at f (.next/server/app/server/page.js:2:13549)
at stringify () {
digest: '891653235'
}

Root cause (verified by reading the installed source):
In packages/next/src/build/swc/options.ts (webpack path), the isServer
branch hardcodes env: { targets: { node: process.versions.node } } and
never spreads swcEnvOptions, while the client branch correctly does
env: { targets: supportedBrowsers, ...swcEnvOptions }.

Provide environment information

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 25.2.0
Binaries:
  Node: 22.22.2
  npm: 10.9.7
  pnpm: 10.33.2
Relevant Packages:
  next: 16.3.0-canary.5
  react: 19.2.4
  react-dom: 19.2.4
  typescript: 5.9.3
Next.js Config:
  output: N/A

Which area(s) are affected? (Select all that apply)

Turbopack

Which stage(s) are affected? (Select all that apply)

next build (local), next start (local)

Additional context

No response

Start with packages/next/src/build/swc/options.ts and inspect the isServer branch alongside the client branch that applies swcEnvOptions. Reproduce the failure from izemo/izemo-next-app with pnpm build --webpack, then verify that the server bundle includes the core-js polyfill and the /server route works under Node 22.22.2.