Pass nextRuntime in webpack context

[ijjk]

Follow-up to #36383 this also exposes the nextRuntime for the custom webpack function in next.config.js to allow differentiating between the environments.

x-ref: https://vercel.slack.com/archives/CGU8HUTUH/p1647866770704939

[huozhi]

Nice 👍

[ijjk]

Stats from current PR

Default Build (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	ijjk/next.js add/webpack-next-runtime	Change
buildDuration	15.4s	15.5s	⚠️ +108ms
buildDurationCached	6.1s	6.2s	⚠️ +60ms
nodeModulesSize	481 MB	481 MB	⚠️ +292 B

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	ijjk/next.js add/webpack-next-runtime	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.217	3.25	⚠️ +0.03
/ avg req/sec	777.19	769.18	⚠️ -8.01
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.351	1.356	⚠️ +0.01
/error-in-render avg req/sec	1850.35	1843.01	⚠️ -7.34

Client Bundles (main, webpack)

	vercel/next.js canary	ijjk/next.js add/webpack-next-runtime	Change
925.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42 kB	42 kB	✓
main-HASH.js gzip	28.6 kB	28.6 kB	✓
webpack-HASH.js gzip	1.44 kB	1.44 kB	✓
Overall change	72.3 kB	72.3 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	ijjk/next.js add/webpack-next-runtime	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	ijjk/next.js add/webpack-next-runtime	Change
_app-HASH.js gzip	1.36 kB	1.36 kB	✓
_error-HASH.js gzip	192 B	192 B	✓
amp-HASH.js gzip	309 B	309 B	✓
css-HASH.js gzip	327 B	327 B	✓
dynamic-HASH.js gzip	3.08 kB	3.08 kB	✓
head-HASH.js gzip	357 B	357 B	✓
hooks-HASH.js gzip	920 B	920 B	✓
image-HASH.js gzip	5.73 kB	5.73 kB	✓
index-HASH.js gzip	263 B	263 B	✓
link-HASH.js gzip	2.63 kB	2.63 kB	✓
routerDirect..HASH.js gzip	320 B	320 B	✓
script-HASH.js gzip	392 B	392 B	✓
withRouter-HASH.js gzip	319 B	319 B	✓
85e02e95b279..7e3.css gzip	107 B	107 B	✓
Overall change	16.3 kB	16.3 kB	✓

Client Build Manifests

	vercel/next.js canary	ijjk/next.js add/webpack-next-runtime	Change
_buildManifest.js gzip	459 B	459 B	✓
Overall change	459 B	459 B	✓

Rendered Page Sizes

	vercel/next.js canary	ijjk/next.js add/webpack-next-runtime	Change
index.html gzip	531 B	531 B	✓
link.html gzip	545 B	545 B	✓
withRouter.html gzip	526 B	526 B	✓
Overall change	1.6 kB	1.6 kB	✓

---

Default Build with SWC (Decrease detected ✓)

General Overall increase ⚠️

	vercel/next.js canary	ijjk/next.js add/webpack-next-runtime	Change
buildDuration	17.6s	18.1s	⚠️ +469ms
buildDurationCached	6.1s	6s	-112ms
nodeModulesSize	481 MB	481 MB	⚠️ +292 B

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	ijjk/next.js add/webpack-next-runtime	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3.279	3.231	-0.05
/ avg req/sec	762.38	773.76	+11.38
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.372	1.39	⚠️ +0.02
/error-in-render avg req/sec	1822	1799.15	⚠️ -22.85

Client Bundles (main, webpack)

	vercel/next.js canary	ijjk/next.js add/webpack-next-runtime	Change
925.HASH.js gzip	178 B	178 B	✓
framework-HASH.js gzip	42.2 kB	42.2 kB	✓
main-HASH.js gzip	29.1 kB	29.1 kB	✓
webpack-HASH.js gzip	1.45 kB	1.45 kB	✓
Overall change	72.9 kB	72.9 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	ijjk/next.js add/webpack-next-runtime	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	ijjk/next.js add/webpack-next-runtime	Change
_app-HASH.js gzip	1.35 kB	1.35 kB	✓
_error-HASH.js gzip	179 B	179 B	✓
amp-HASH.js gzip	313 B	313 B	✓
css-HASH.js gzip	325 B	325 B	✓
dynamic-HASH.js gzip	3.08 kB	3.08 kB	✓
head-HASH.js gzip	359 B	359 B	✓
hooks-HASH.js gzip	921 B	921 B	✓
image-HASH.js gzip	5.78 kB	5.78 kB	✓
index-HASH.js gzip	261 B	261 B	✓
link-HASH.js gzip	2.74 kB	2.74 kB	✓
routerDirect..HASH.js gzip	322 B	322 B	✓
script-HASH.js gzip	393 B	393 B	✓
withRouter-HASH.js gzip	317 B	317 B	✓
85e02e95b279..7e3.css gzip	107 B	107 B	✓
Overall change	16.5 kB	16.5 kB	✓

Client Build Manifests

	vercel/next.js canary	ijjk/next.js add/webpack-next-runtime	Change
_buildManifest.js gzip	458 B	458 B	✓
Overall change	458 B	458 B	✓

Rendered Page Sizes

	vercel/next.js canary	ijjk/next.js add/webpack-next-runtime	Change
index.html gzip	530 B	530 B	✓
link.html gzip	542 B	542 B	✓
withRouter.html gzip	524 B	524 B	✓
Overall change	1.6 kB	1.6 kB	✓

Commit: 56e249c