Auto-provision older simulators.

Make.config

@@ -98,6 +98,8 @@ MIN_WATCHOS_SIMULATOR_VERSION=2.0
 # This is the iOS version that matches the watchOS version (i.e same Xcode)
 MIN_WATCHOS_COMPANION_SIMULATOR_VERSION=9.0
 MIN_TVOS_SIMULATOR_VERSION=9.0
+# These are the simulator package ids for the versions above
+EXTRA_SIMULATORS+=" com.apple.pkg.iPhoneSimulatorSDK8_1 com.apple.pkg.iPhoneSimulatorSDK9_0 com.apple.pkg.AppleTVSimulatorSDK9_0 com.apple.pkg.WatchSimulatorSDK2_0"
 
 INCLUDE_IOS=1
 INCLUDE_MAC=1