Add next dynamic swc transform

[padmaia]

Ported packages/next/build/babel/plugins/react-loadable-plugin.ts to swc

[padmaia]

Do we still need to support dynamic(import('something'))? There was a comment that said it would deprecated, but not sure if that ever happened.

[timneutkens]

Do we still need to support dynamic(import('something'))? There was a comment that said it would deprecated, but not sure if that ever happened.

I think it's fine to leave it out for now 👍

[kdy1]

Mostly LGTM, but I think error messages can be improved.

[ijjk]

Stats from current PR

Default Build

General

	vercel/next.js canary	padmaia/next.js add/react-loadable-swc	Change
buildDuration	16.8s	16.7s	-140ms
buildDurationCached	3.8s	3.7s	-123ms
nodeModulesSize	50.2 MB	50.2 MB	✓

Page Load Tests Overall increase ✓

	vercel/next.js canary	padmaia/next.js add/react-loadable-swc	Change
/ failed reqs	0	0	✓
/ total time (seconds)	2.974	3.014	⚠️ +0.04
/ avg req/sec	840.74	829.5	⚠️ -11.24
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.888	1.867	-0.02
/error-in-render avg req/sec	1324.36	1339.07	+14.71

Client Bundles (main, webpack, commons)

	vercel/next.js canary	padmaia/next.js add/react-loadable-swc	Change
745.HASH.js gzip	179 B	179 B	✓
framework-HASH.js gzip	42.2 kB	42.2 kB	✓
main-HASH.js gzip	23.1 kB	23.1 kB	✓
webpack-HASH.js gzip	1.5 kB	1.5 kB	✓
Overall change	67 kB	67 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	padmaia/next.js add/react-loadable-swc	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	padmaia/next.js add/react-loadable-swc	Change
_app-HASH.js gzip	980 B	980 B	✓
_error-HASH.js gzip	194 B	194 B	✓
amp-HASH.js gzip	312 B	312 B	✓
css-HASH.js gzip	329 B	329 B	✓
dynamic-HASH.js gzip	2.52 kB	2.52 kB	✓
head-HASH.js gzip	350 B	350 B	✓
hooks-HASH.js gzip	904 B	904 B	✓
image-HASH.js gzip	4.12 kB	4.12 kB	✓
index-HASH.js gzip	261 B	261 B	✓
link-HASH.js gzip	1.66 kB	1.66 kB	✓
routerDirect..HASH.js gzip	319 B	319 B	✓
script-HASH.js gzip	387 B	387 B	✓
withRouter-HASH.js gzip	320 B	320 B	✓
bb14e60e810b..30f.css gzip	125 B	125 B	✓
Overall change	12.8 kB	12.8 kB	✓

Client Build Manifests

	vercel/next.js canary	padmaia/next.js add/react-loadable-swc	Change
_buildManifest.js gzip	490 B	490 B	✓
Overall change	490 B	490 B	✓

Rendered Page Sizes

	vercel/next.js canary	padmaia/next.js add/react-loadable-swc	Change
index.html gzip	531 B	531 B	✓
link.html gzip	542 B	542 B	✓
withRouter.html gzip	523 B	523 B	✓
Overall change	1.6 kB	1.6 kB	✓

---

Webpack 4 Mode (Decrease detected ✓)

General

	vercel/next.js canary	padmaia/next.js add/react-loadable-swc	Change
buildDuration	13s	13s	-21ms
buildDurationCached	5.2s	5s	-122ms
nodeModulesSize	50.2 MB	50.2 MB	✓

Page Load Tests Overall decrease ⚠️

	vercel/next.js canary	padmaia/next.js add/react-loadable-swc	Change
/ failed reqs	0	0	✓
/ total time (seconds)	3	2.999	0
/ avg req/sec	833.34	833.51	+0.17
/error-in-render failed reqs	0	0	✓
/error-in-render total time (seconds)	1.783	1.844	⚠️ +0.06
/error-in-render avg req/sec	1402.17	1355.45	⚠️ -46.72

Client Bundles (main, webpack, commons)

	vercel/next.js canary	padmaia/next.js add/react-loadable-swc	Change
17.HASH.js gzip	185 B	185 B	✓
677f882d2ed8..HASH.js gzip	14 kB	14 kB	✓
framework.HASH.js gzip	41.9 kB	41.9 kB	✓
main-HASH.js gzip	10.6 kB	10.6 kB	✓
webpack-HASH.js gzip	1.19 kB	1.19 kB	✓
Overall change	67.8 kB	67.8 kB	✓

Legacy Client Bundles (polyfills)

	vercel/next.js canary	padmaia/next.js add/react-loadable-swc	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	padmaia/next.js add/react-loadable-swc	Change
_app-HASH.js gzip	965 B	965 B	✓
_error-HASH.js gzip	3.71 kB	3.71 kB	✓
amp-HASH.js gzip	552 B	552 B	✓
css-HASH.js gzip	333 B	333 B	✓
dynamic-HASH.js gzip	2.71 kB	2.71 kB	✓
head-HASH.js gzip	2.97 kB	2.97 kB	✓
hooks-HASH.js gzip	911 B	911 B	✓
index-HASH.js gzip	231 B	231 B	✓
link-HASH.js gzip	1.64 kB	1.64 kB	✓
routerDirect..HASH.js gzip	298 B	298 B	✓
script-HASH.js gzip	2.94 kB	2.94 kB	✓
withRouter-HASH.js gzip	294 B	294 B	✓
e025d2764813..52f.css gzip	125 B	125 B	✓
Overall change	17.7 kB	17.7 kB	✓

Client Build Manifests

	vercel/next.js canary	padmaia/next.js add/react-loadable-swc	Change
_buildManifest.js gzip	498 B	498 B	✓
Overall change	498 B	498 B	✓

Rendered Page Sizes

	vercel/next.js canary	padmaia/next.js add/react-loadable-swc	Change
index.html gzip	576 B	576 B	✓
link.html gzip	589 B	589 B	✓
withRouter.html gzip	570 B	570 B	✓
Overall change	1.74 kB	1.74 kB	✓

Commit: 31c46da