Prefices starting with _ are not supported by DartVM

[DartBot]

This issue was originally filed by antonm@google.com

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Dart spec is not quite precise what are allowed prefices, but the following Dart code:

import('dart:core', prefix: '_p');

main() {
  print(new _p.List<int>());
}

gives:

zsh/3 368 20-[master]-% ./out/ReleaseIA32/dart t.dart
'file:///usr/local/google/home/antonm/dart-proper/dart/t.dart': Error: line 3 pos 13: type '_p@3a99ae38' is not loaded
  print(new _p.List<int>());
            ^

under DartVM.

[DartBot]

This comment was originally written by antonm@google.com

[iposva-google]

The problem here is that the prefix is passed as a string, so the automatic mangling is side-stepped when importing the library.

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Set owner to @iposva-google.

[iposva-google]

Added Accepted label.

[iposva-google]

This has automatically been fixed by using the new import syntax. The corrected program below now prints what you would expect.

import "dart:core" as _core;

main() {
  _core.print(new _core.List<_core.int>());
}

dart ~/dart/Bug.dart
[]

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cc @mhausner.
Added Fixed label.