Upload gen_snapshot/dartaotruntime for linux arm/riscv64 cross compile.

Issue: https://github.com/dart-lang/sdk/issues/28617
Change-Id: Idc1c43bb070f2585ef4d919fa3ec9e21a216b6df
Reviewed-on: https://dart-review.googlesource.com/c/recipes/+/437740
Reviewed-by: Ivan Inozemtsev <iinozemtsev@google.com>
Commit-Queue: Tess Strickland <sstrickl@google.com>
7 files changed