Revert "Enable Dart 2.0 fixed-size integers in Flutter (#4337)" (#4344)
Revert "Enable Dart 2.0 fixed-size integers in Flutter (#4337)" (#4344)

This reverts commit 0b7582e6a130fc99270dafec5113a7ec46ed522a.
chinmaygarde/flutter_engine,tvolkert/engine,tvolkert/engine,rmacnak-google/engine,aam/engine,rmacnak-google/engine,cdotstout/sky_engine,Hixie/sky_engine,cdotstout/sky_engine,mikejurka/engine,jamesr/flutter_engine,jason-simmons/flutter_engine,jason-simmons/flutter_engine,chinmaygarde/sky_engine,jamesr/sky_engine,rmacnak-google/engine,chinmaygarde/sky_engine,chinmaygarde/sky_engine,jason-simmons/sky_engine,tvolkert/engine,aam/engine,mikejurka/engine,jamesr/sky_engine,chinmaygarde/sky_engine,krisgiesing/sky_engine,jason-simmons/flutter_engine,devoncarew/sky_engine,aam/engine,chinmaygarde/sky_engine,rmacnak-google/engine,flutter/engine,aam/engine,mikejurka/engine,devoncarew/engine,jamesr/flutter_engine,tvolkert/engine,Hixie/sky_engine,jamesr/sky_engine,mikejurka/engine,chinmaygarde/sky_engine,flutter/engine,jason-simmons/sky_engine,devoncarew/sky_engine,flutter/engine,mikejurka/engine,Hixie/sky_engine,jason-simmons/sky_engine,flutter/engine,jamesr/flutter_engine,jamesr/sky_engine,mikejurka/engine,aam/engine,mikejurka/engine,jason-simmons/sky_engine,devoncarew/engine,cdotstout/sky_engine,jason-simmons/sky_engine,tvolkert/engine,jason-simmons/flutter_engine,jamesr/sky_engine,rmacnak-google/engine,devoncarew/engine,Hixie/sky_engine,krisgiesing/sky_engine,tvolkert/engine,krisgiesing/sky_engine,jason-simmons/flutter_engine,jason-simmons/flutter_engine,devoncarew/sky_engine,mikejurka/engine,flutter/engine,devoncarew/sky_engine,jamesr/flutter_engine,cdotstout/sky_engine,jamesr/sky_engine,krisgiesing/sky_engine,devoncarew/sky_engine,Hixie/sky_engine,cdotstout/sky_engine,devoncarew/engine,jamesr/flutter_engine,jamesr/flutter_engine,krisgiesing/sky_engine,cdotstout/sky_engine,Hixie/sky_engine,jason-simmons/sky_engine,chinmaygarde/flutter_engine,aam/engine,chinmaygarde/flutter_engine,jamesr/flutter_engine,chinmaygarde/flutter_engine,krisgiesing/sky_engine,chinmaygarde/flutter_engine,devoncarew/sky_engine,jamesr/flutter_engine,jamesr/flutter_engine,devoncarew/engine,krisgiesing/sky_engine,jason-simmons/flutter_engine,flutter/engine,chinmaygarde/flutter_engine,rmacnak-google/engine,devoncarew/engine,flutter/engine,flutter/engine,chinmaygarde/sky_engine,aam/engine,devoncarew/sky_engine,jason-simmons/sky_engine,aam/engine,chinmaygarde/flutter_engine,Hixie/sky_engine,jason-simmons/flutter_engine,cdotstout/sky_engine,Hixie/sky_engine,jamesr/sky_engine,tvolkert/engine,devoncarew/engine,rmacnak-google/engine,mikejurka/engine