dec87b98f0
Instead of requiring embedder to initialize dart:io by bits and pieces by invoking various hooks and setting fields provide a structured C++ API for preparing dart:io for execution. TEST=ci CoreLibraryReviewExempt: VM specific changes only Change-Id: I66e95c0a451d384b4f7582d1df059e506a6a6964 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/454062 Reviewed-by: Ryan Macnak <rmacnak@google.com> Commit-Queue: Slava Egorov <vegorov@google.com>