488ba69e41
Implement api methods to create and shutdown isolates from IsolateGroup-bound callbacks (normally invoked from native code), run dart code on such isolates. The rest of the api is not implemented yet. TEST=tests/ffi/threading_test.dart BUG=https://github.com/dart-lang/sdk/issues/62407 CoreLibraryReviewExempt: vm-only change to isolate library Change-Id: I0271ead8ba011dfe9d7953769415d6a88a962854 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/486522 Commit-Queue: Alexander Aprelev <aam@google.com> Reviewed-by: Ryan Macnak <rmacnak@google.com>