* Reland: [flutter_tool] Where possible, catch only subtypes of Exception

* Add armv7f to getIOSArchForName

This reverts commit aed96199.

Revert "[flutter_tools] Allow providing dart-defines to Android, iOS, macOS builds (#51714)" (#52041)

This reverts commit ee60eeea.

* [flutter_tools] supports tree-shake-icons for web builds

* Update compile.dart

* fix icon_tree_shaker

This reverts commit 57c6721c.

This reverts commit 9de7787f.

This reverts commit f1cd47ef.

* 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

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

* 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

Slight cleanup of file locations in flutter_tools
to make it easier to see which files are responsible
for data reporting.