a3d1e1a606
When running the test runner without a specified architecture, it should default to the host architecture instead of hard-coded x64. This matters especially on all new Macs as those are arm64 Change-Id: I6cde0ff7d42aaf7eed31649b39b26d00198197c6 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/426463 Reviewed-by: Alexander Thomas <athom@google.com> Commit-Queue: Martin Kustermann <kustermann@google.com>