41862 Make output directory a build input

41989 Flutter doctor should require java 1.8+

42008 Restructure ProjectFileInvalidator.findInvalidated a bit

42016 [flutter_tool] Re-work analytics events to use labels and values

42026 Stop leaking iproxy processes

42028 Make ProjectFileInvalidator.findInvalidated able to use the async FileStat.stat

42187 Be more verbose when pub fails

42209 Add error logging to flutter generate

42243 Improve trailing whitespace message

42252 catch argument error from Make

42353 Add –cache-sksl flag to drive and run