* Update page-loader prefetch checking

* Add test for re-prefetching same bundle

* Fix TypeScript typing
This correctly defines `process.browser` instead of `process.env.browser`.

It also removes `process.crossOrigin` because it's not found in our documentation anywhere and is mostly used for internal purposes.

* Make sure `process.browser` doesn't throw a type error

* Split globals from Next.js module

* Allow `test` as a valid NODE_ENV

* Fix type assignment

* Make sure global types get published

* Fix test

* Restoring not working mouse event

* Restoring possibility of conditionally switching off the prefetch

This PR compiles development-time dependencies that cause invalid syntax errors in IE 11 (ES 5).

Closes #7610
Closes #7612

* `_document` middleware is experimental

Closes https://github.com/zeit/next.js/issues/7580

* Turn on document middleware

This reverts commit e85a517e.

* Removed eslint packages and module-resolver from the example

* Removed unused package

* Reimplement ncc webpack build

This reverts commit 6feca310.

* Shared webpack build

* ncc workaround pending @zeit/ncc#437

* update ncc

* build tweaks, fixup autodll-import

* possible Node 8 fix

* second possible Node 8 fix

* and update taskfile

* Dynamic Routes: Change impl from $param to [param]

* Update expected test snapshot

* Update test to use new syntax

* Update test file

* Test more behavior

* Update route sorter for new param syntax

* Update dynamic routing tests

* Update danging test file

* Tweak test

* Fix dev and update tests

This should allow Terser to tree shake code branches.

* Correctly define NODE_ENV and `process.browser`

* Add crossOrigin property

Fix typo

* Re-require all module information for client-side initializers list
We really should re-work how our loadable code words, because this passes an excessive number of modules to the client.

In the ideal world, we only pass the entry module id of each chunk, but there's no point in investing the time until we switch to webpack 5 which completely revamps the chunk graph API.

* Get a unique set of ids

* Update getInitialprops docs

* Update docs for prefetch

* Updated prefetch docs

* Removed hotSelfAccept from docs and othr changes

* Prefer /public

* dots dots dots dots

* Added docs for Automatic Pre-rendering

* Added a note to <Link />

* Removed 404 example

* Added references for Automatic pre-rendering

* Added a typescript section for AMP

* Executed doctoc again to add AMP sections

* Properly explain automatic pre-rendering

* Switch back to LF

* Apply corrections
Co-Authored-By: NJoe Haddad <timer150@gmail.com>

* Minor corrections

* Added back some periods

* Added back some periods

* Add handling for invalid pages during autoExport

* Add err.sh link for invalid page export

* Fix typo

* Apply suggestions from code review
Co-Authored-By: NTim Neutkens <tim@timneutkens.nl>

This adjusts our default terser configuration to not break seemingly valid JavaScript code.

Closes #7178
Closes #7496