Fix "env" key in babelrc with new Babel mode

[timneutkens]

Fixes an issue where "env" would be ignored and would crash if there was no top level "presets". Also found that webpack did not invalidate the cache on changes to the babel config, so I also fixed that.

Bug

• Related issues linked using fixes #number
• Integration tests added

Feature

• Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
• Related issues linked using fixes #number
• Integration tests added
• Documentation added
• Telemetry added. In case of a feature if it's used or not.

Documentation / Examples

• Make sure the linting passes

[ijjk]

Stats from current PR

Default Server Mode (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
buildDuration	13.2s	13.3s	⚠️ +49ms
buildDurationCached	3.2s	3.2s	-8ms
nodeModulesSize	46.6 MB	46.6 MB	⚠️ +92 B

Page Load Tests Overall increase ✓

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.619	2.647	⚠️ +0.03
/ avg req/sec	954.46	944.42	⚠️ -10.04
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.343	1.318	-0.02
/error-in-render avg req/sec	1861.81	1897.43	+35.62

Client Bundles (main, webpack, commons)

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
framework-HASH.js gzip	39.3 kB	39.3 kB	✓
main-HASH.js gzip	20.2 kB	20.2 kB	✓
webpack-HASH.js gzip	804 B	804 B	✓
Overall change	60.3 kB	60.3 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
polyfills-HASH.js gzip	31.1 kB	31.1 kB	✓
Overall change	31.1 kB	31.1 kB	✓

Client Pages

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
_app-HASH.js gzip	801 B	801 B	✓
_error-HASH.js gzip	3.07 kB	3.07 kB	✓
amp-HASH.js gzip	527 B	527 B	✓
css-HASH.js gzip	334 B	334 B	✓
hooks-HASH.js gzip	890 B	890 B	✓
index-HASH.js gzip	263 B	263 B	✓
link-HASH.js gzip	1.64 kB	1.64 kB	✓
routerDirect..HASH.js gzip	333 B	333 B	✓
withRouter-HASH.js gzip	330 B	330 B	✓
bb14e60e810b..30f.css gzip	125 B	125 B	✓
Overall change	8.31 kB	8.31 kB	✓

Client Build Manifests

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
_buildManifest.js gzip	392 B	392 B	✓
Overall change	392 B	392 B	✓

Rendered Page Sizes

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
index.html gzip	571 B	571 B	✓
link.html gzip	579 B	579 B	✓
withRouter.html gzip	567 B	567 B	✓
Overall change	1.72 kB	1.72 kB	✓

---

Serverless Mode (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
buildDuration	15s	14.6s	-410ms
buildDurationCached	4.3s	4.3s	⚠️ +30ms
nodeModulesSize	46.6 MB	46.6 MB	⚠️ +92 B

Client Bundles (main, webpack, commons)

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
framework-HASH.js gzip	39.3 kB	39.3 kB	✓
main-HASH.js gzip	20.2 kB	20.2 kB	✓
webpack-HASH.js gzip	804 B	804 B	✓
Overall change	60.3 kB	60.3 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
polyfills-HASH.js gzip	31.1 kB	31.1 kB	✓
Overall change	31.1 kB	31.1 kB	✓

Client Pages

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
_app-HASH.js gzip	801 B	801 B	✓
_error-HASH.js gzip	3.07 kB	3.07 kB	✓
amp-HASH.js gzip	527 B	527 B	✓
css-HASH.js gzip	334 B	334 B	✓
hooks-HASH.js gzip	890 B	890 B	✓
index-HASH.js gzip	263 B	263 B	✓
link-HASH.js gzip	1.64 kB	1.64 kB	✓
routerDirect..HASH.js gzip	333 B	333 B	✓
withRouter-HASH.js gzip	330 B	330 B	✓
bb14e60e810b..30f.css gzip	125 B	125 B	✓
Overall change	8.31 kB	8.31 kB	✓

Client Build Manifests

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
_buildManifest.js gzip	392 B	392 B	✓
Overall change	392 B	392 B	✓

Serverless bundles Overall decrease ✓

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
_error.js	16.9 kB	16.9 kB	✓
404.html	2.44 kB	2.44 kB	✓
500.html	2.43 kB	2.43 kB	✓
amp.amp.html	10.8 kB	10.8 kB	✓
amp.html	1.63 kB	1.63 kB	✓
css.html	1.81 kB	1.81 kB	✓
hooks.html	1.69 kB	1.69 kB	✓
index.js	17.2 kB	17.2 kB	-2 B
link.js	17.4 kB	17.4 kB	✓
routerDirect.js	17.4 kB	17.4 kB	-2 B
withRouter.js	17.4 kB	17.4 kB	✓
Overall change	107 kB	107 kB	-4 B

---

Webpack 4 Mode (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
buildDuration	11.7s	11.7s	⚠️ +13ms
buildDurationCached	4.8s	4.8s	⚠️ +13ms
nodeModulesSize	46.6 MB	46.6 MB	⚠️ +92 B

Page Load Tests Overall increase ✓

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.69	2.651	-0.04
/ avg req/sec	929.44	942.97	+13.53
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.343	1.289	-0.05
/error-in-render avg req/sec	1861.2	1939.22	+78.02

Client Bundles (main, webpack, commons)

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
677f882d2ed8..HASH.js gzip	13.3 kB	13.3 kB	✓
framework.HASH.js gzip	39 kB	39 kB	✓
main-HASH.js gzip	7.99 kB	7.99 kB	✓
webpack-HASH.js gzip	751 B	751 B	✓
Overall change	61.1 kB	61.1 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
polyfills-HASH.js gzip	31.3 kB	31.3 kB	✓
Overall change	31.3 kB	31.3 kB	✓

Client Pages

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
_app-HASH.js gzip	1.07 kB	1.07 kB	✓
_error-HASH.js gzip	3.74 kB	3.74 kB	✓
amp-HASH.js gzip	536 B	536 B	✓
css-HASH.js gzip	339 B	339 B	✓
hooks-HASH.js gzip	887 B	887 B	✓
index-HASH.js gzip	227 B	227 B	✓
link-HASH.js gzip	1.63 kB	1.63 kB	✓
routerDirect..HASH.js gzip	303 B	303 B	✓
withRouter-HASH.js gzip	302 B	302 B	✓
e025d2764813..52f.css gzip	125 B	125 B	✓
Overall change	9.16 kB	9.16 kB	✓

Client Build Manifests

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
_buildManifest.js gzip	420 B	420 B	✓
Overall change	420 B	420 B	✓

Rendered Page Sizes

	vercel/next.js canary	timneutkens/next.js fix/env-babelrc	Change
index.html gzip	626 B	626 B	✓
link.html gzip	632 B	632 B	✓
withRouter.html gzip	620 B	620 B	✓
Overall change	1.88 kB	1.88 kB	✓

Commit: 8c002b8