Support arm64 macOS via Rosetta2

Author: errikos

mx.py

@@ -3853,6 +3853,11 @@ def get_arch():
         except OSError:
             # sysctl is not available
             pass
+    if machine == 'arm64' and is_darwin():
+    # temporary workaround for arm64 (aarch64) based macOS systems (e.g. M1 processor)
+    # some libraries don't have a macOS arm64 build yet (e.g. ASYNC_PROFILER),
+    # but they can run as amd64 with Rosetta2
+        return 'amd64'
     abort('unknown or unsupported architecture: os=' + get_os() + ', machine=' + machine)
 
 mx_subst.results_substitutions.register_no_arg('arch', get_arch)