e50b7e77b8
This adds support for generating truly unique fresh names when building augmentation library code. The synthesized names are used for import prefixes and as placeholders for not-yet-inferred omitted type annotations. Change-Id: I6fe9bc37b39a243c93187f561ee32e07237341f1 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/237823 Reviewed-by: Jake Macdonald <jakemac@google.com> Commit-Queue: Johnni Winther <johnniwinther@google.com>