Add iOS simulator launch scripts

scripts/check-ios-prereqs.sh

@@ -10,4 +10,10 @@ xcodebuild -version
 xcrun simctl list devices available
 swift --version
 
+if ! xcrun simctl list devices available | grep -Eq 'iPhone|iPad'; then
+  printf 'No available iOS simulator devices found. Install the iOS platform from Xcode Settings > Components or run:\n' >&2
+  printf '  DEVELOPER_DIR=/Applications/Xcode.app/Contents/Developer xcodebuild -downloadPlatform iOS\n' >&2
+  exit 1
+fi
+
 printf 'iOS prerequisites are available.\n'