Roll Dart forward to 8dc35ba47ee5f43e0f6ed8d9b6a3914a2c4d9577 (#2815)
Roll Dart forward to 8dc35ba47ee5f43e0f6ed8d9b6a3914a2c4d9577 (#2815)

- [x] Fixes devfs opening too many files.
- [x] Build fixes related to Fuschia support
jason-simmons/sky_engine,chinmaygarde/flutter_engine,krisgiesing/sky_engine,cdotstout/sky_engine,jason-simmons/flutter_engine,abarth/sky_engine,abarth/sky_engine,mpcomplete/engine,aam/engine,abarth/sky_engine,mikejurka/engine,jason-simmons/sky_engine,jason-simmons/flutter_engine,mpcomplete/engine,aam/engine,flutter/engine,tvolkert/engine,flutter/engine,devoncarew/engine,jason-simmons/flutter_engine,mikejurka/engine,chinmaygarde/flutter_engine,rmacnak-google/engine,flutter/engine,cdotstout/sky_engine,mpcomplete/engine,Hixie/sky_engine,mikejurka/engine,mikejurka/engine,mpcomplete/flutter_engine,jason-simmons/sky_engine,jamesr/flutter_engine,devoncarew/engine,rmacnak-google/engine,cdotstout/sky_engine,Hixie/sky_engine,Hixie/sky_engine,krisgiesing/sky_engine,krisgiesing/sky_engine,jamesr/flutter_engine,chinmaygarde/flutter_engine,jamesr/flutter_engine,mpcomplete/engine,devoncarew/sky_engine,chinmaygarde/sky_engine,chinmaygarde/flutter_engine,chinmaygarde/sky_engine,krisgiesing/sky_engine,cdotstout/sky_engine,mpcomplete/flutter_engine,jamesr/flutter_engine,devoncarew/sky_engine,flutter/engine,mpcomplete/engine,jamesr/sky_engine,jamesr/sky_engine,jamesr/sky_engine,jamesr/sky_engine,chinmaygarde/sky_engine,rmacnak-google/engine,devoncarew/engine,tvolkert/engine,cdotstout/sky_engine,abarth/sky_engine,chinmaygarde/sky_engine,aam/engine,devoncarew/engine,aam/engine,cdotstout/sky_engine,jason-simmons/flutter_engine,rmacnak-google/engine,jamesr/sky_engine,tvolkert/engine,devoncarew/sky_engine,abarth/sky_engine,mpcomplete/engine,mpcomplete/engine,jason-simmons/flutter_engine,devoncarew/sky_engine,mikejurka/engine,rmacnak-google/engine,chinmaygarde/flutter_engine,mikejurka/engine,jason-simmons/flutter_engine,mpcomplete/flutter_engine,tvolkert/engine,flutter/engine,mpcomplete/engine,abarth/sky_engine,chinmaygarde/flutter_engine,jason-simmons/sky_engine,abarth/sky_engine,Hixie/sky_engine,jamesr/sky_engine,mikejurka/engine,jason-simmons/flutter_engine,chinmaygarde/sky_engine,tvolkert/engine,mpcomplete/flutter_engine,chinmaygarde/flutter_engine,Hixie/sky_engine,aam/engine,jamesr/flutter_engine,cdotstout/sky_engine,krisgiesing/sky_engine,jamesr/sky_engine,krisgiesing/sky_engine,rmacnak-google/engine,devoncarew/sky_engine,jason-simmons/flutter_engine,mpcomplete/flutter_engine,jamesr/flutter_engine,tvolkert/engine,jamesr/flutter_engine,jason-simmons/sky_engine,flutter/engine,jamesr/flutter_engine,devoncarew/sky_engine,rmacnak-google/engine,mpcomplete/flutter_engine,devoncarew/engine,Hixie/sky_engine,jason-simmons/sky_engine,Hixie/sky_engine,devoncarew/sky_engine,chinmaygarde/sky_engine,Hixie/sky_engine,flutter/engine,krisgiesing/sky_engine,devoncarew/engine,mikejurka/engine,flutter/engine,aam/engine,mikejurka/engine,jamesr/flutter_engine,tvolkert/engine,jason-simmons/sky_engine,aam/engine,devoncarew/engine,chinmaygarde/sky_engine,aam/engine