[infra] Fix architecture detection on M1/arm64 macs

Change-Id: I678054cbe27965cd552020ebc73fecebc6c6224d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/237422
Reviewed-by: William Hesse <whesse@google.com>
Commit-Queue: Alexander Thomas <athom@google.com>
Reviewed-by: Ömer Ağacan <omersa@google.com>
diff --git a/tools/utils.py b/tools/utils.py
index cecdbc2..3741a0b 100644
--- a/tools/utils.py
+++ b/tools/utils.py
@@ -154,10 +154,10 @@
     os_id = platform.machine()
     if os_id.startswith('armv6'):
         return 'armv6'
+    elif os_id.startswith('aarch64') or os_id == 'arm64':
+        return 'arm64'
     elif os_id.startswith('arm'):
         return 'arm'
-    elif os_id.startswith('aarch64'):
-        return 'arm64'
     elif '64' in os_id:
         return 'x64'
     elif (not os_id) or (not re.match('(x|i[3-6])86', os_id) is None):