36135 add a kIsWeb constant to foundation (cla: yes, framework)

36138 Implement feature flag system for flutter tools (cla: yes, tool)

36174 [cupertino_icons] Add glyph refs for brightness #16102 (cla: yes, f: cupertino, framework)

36194 Keep LLDB connection to iOS device alive while running from CLI.  (cla: yes, tool)

36197 Fix windows, exclude widgets from others (cla: yes, team)

36199 Don’t try to flutterExit if isolate is still paused (cla: yes, tool)

36200 Refactoring the Android_views tests app to prepare for adding the iOS platform view tests (a: platform-views, a: tests, cla: yes, team)