This adds our self-compiled copy of the MinGit executable (built from the flutter/git repo) to the archive when building an archive for Windows.
I also tweaked the internal API for prepare_package.dart so that there's a single entry point to build an archive.
* fix updrade script; upgrade to the latest package versions
* exclude special dependencies from transitive closure
* fix stack trace handling in flutter_test due to stack_trace change
* change type on _emptyStackTrace
* Pin all dependencies ONCE AND FOR ALL
This replaces the secret `flutter update-packages --upgrade` with a destructive `flutter update-packages --force-upgrade` that actually goes and pins every dependency and transitive dependency in every flutter package to the same version.
* Add comments.
* Remove the workaround that pinned args to v0.13.6
This reverts most of the changes in commit 6331b6c8b5
* throw exception if exit code is not an integer
* rework command infrastructure to throw ToolExit when non-zero exitCode
* convert commands to return Future<Null>
* cleanup remaining commands to use throwToolExit for non-zero exit code
* remove isUnusual exception message
* add type annotations for updated args package
Switch our pubspec.yamls to using SDK sources so that we can have consistent
source types when we depend on these packages from external packages using SDK
sources.
