This is an attempt to enable archiving of coredumps on the
"iso-stress" builder, since we're often unable to reproduce crashes from
that builder.
Issue https://github.com/dart-lang/sdk/issues/46823
TEST=Adds test infra.
Change-Id: I9b7276198db9a6c98a74f55d466bf832b03e24f8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/214407
Reviewed-by: Alexander Thomas <athom@google.com>
Reviewed-by: Slava Egorov <vegorov@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
