This uses @kevmoo's completion package to do command line completion for flutter, and a new command "bash-completion" (with alias "zsh-completion") that will output the necessary shell script setup code, and adds the hidden command "completion" that does the actual completion. Because it adds a dependency, I also had to do flutter update-packages --force-upgrade. Fixes #18988.
Flutter Tools
Tools for building Flutter applications.
To run the tests, ensure that no devices are connected,
then navigate to flutter_tools and execute:
../../bin/cache/dart-sdk/bin/pub run test -j1