8d1c4c555c
To enable our tests to spawn a new isolate in a new group, this CL
adds a `{bool newIsolateGroup}` parameter to the internal
`Isolate._spawnFunction` native and moves that native to
`dart:_internal`, thereby allowing runtime/tests/vm/dart/* to access it.
It also adds various tests for lightweight AOT isolates, exercising
GC, communication, spawning, ...
Issue https://github.com/dart-lang/sdk/issues/36097
Change-Id: I3940c30fb43d2475c58e6be78507da74ce64b60d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/145941
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>