This reverts commit 2a113165.

* Update project.pbxproj files to say Flutter rather than Chromium

Also, the templates now have an empty organization so that we don't cause people to give their apps a Flutter copyright.

* Update the copyright notice checker to require a standard notice on all files

* Update copyrights on Dart files. (This was a mechanical commit.)

* Fix weird license headers on Dart files that deviate from our conventions; relicense Shrine.

Some were already marked "The Flutter Authors", not clear why. Their
dates have been normalized. Some were missing the blank line after the
license. Some were randomly different in trivial ways for no apparent
reason (e.g. missing the trailing period).

* Clean up the copyrights in non-Dart files. (Manual edits.)

Also, make sure templates don't have copyrights.

* Fix some more ORGANIZATIONNAMEs

* implicit-casts:false on flutter_tools

* use castStringKeyedMap

* address review comments

* address review comments

* fix issues after rebase

No code changes, just comments: I spell-checked all the comments in the repo.

* implicit-casts:false on flutter_tools/lib

* address review comments

* use castStringKeyedMap

* introduce {bool,string,strings}Arg

* fix ci

* add depfile slot to Target class

* Update source.dart

* Update source.dart

Removes multiple re-entrant calls of bundle and aot and replaces them with a single call to assemble. This restores full caching and will allow follow-up performance improvements when building multiple ABIs

* remove Source.behavior, fix bug in depfile invalidation

* more cleanup of assets

* Add skip

* address comments

* Update build_system.dart

Fixes various Flutter framework test failures when bytecode is enabled.

Reland "AOT support for Linux Desktop I: switch Linux builds to assemble (#41612)" (#42030)" (#42038)

This reverts commit 142a8630.

This reverts commit 3024053c.

Bytecode generation will otherwise omit assert code, causing --enable-asserts to have no effect in the VM.

* Stop using build_runner for dart2js

* fixes to yield when computing hashes and to imports

* add missing await

* Update filecache_test.dart

* Fix paths in filecache test

* use file uri for import

* add test cases and configurable override

* remove test dep

* fix filepaths for windows

* test no longer failing

* fix paths for test cases

* fix typo

* address comments

* make a constant

* make filehash async and use constant

* fix silly logic error