Restart with duplicate class name causes flutter run to hang #19571
Description
If the following app is run with one Foo class definition and then "hot restarted" after a second Foo definition is added, flutter run hangs.
class Foo { }
class Foo { }
void main() { print(new Foo()); }
Performing hot restart...
compiler message: lib/main.dart:61:7: Error: Duplicated definition of 'Foo'.
compiler message: class Foo { }
compiler message: ^
compiler message: lib/main.dart:60:11: Error: Duplicated name: Foo
compiler message: class Foo { }
compiler message: ^
E/flutter ( 4573): [ERROR:flutter/shell/common/engine.cc(151)] Could not prepare to run the isolate.
E/flutter ( 4573): [ERROR:flutter/shell/common/engine.cc(116)] Engine not prepare and launch isolate.