test: simulators on Apple Silicon conform to the stable ABI

Addresses rdar://108788348

Author: edymtt

test/lit.cfg

@@ -919,8 +919,8 @@ if run_os in ('maccatalyst',):
   target_os_abi = 'macosx'
   target_os_is_maccatalyst = "TRUE"
   config.available_features.add("OS=ios")
-# macOS on ASi uses the stable ABI
-if run_os in ('macosx',) and run_cpu in ('arm64',):
+# macOS and simulators on ASi use the stable ABI
+if (run_os in ('macosx',) or 'simulator' in run_environment) and run_cpu in ('arm64',):
   target_mandates_stable_abi = "TRUE"
   config.available_features.add('swift_only_stable_abi')
 if run_os in (